A download manager is a computer program dedicated to the task of downloading (and sometime uploading) possibly unrelated stand-alone files from (and sometime Mac Os Download to) the Internet for storage. This is unlike Mac Os Download a World Wide Web browser, which is mainly intended Mac Os Download to browse web pages, composed of a multitude of smaller files, where error-free moving of files for permanent storage Mac Os Download is of secondary Mac Os Download importance. (A failed or incomplete web page file rarely ruins the page.) The Mac Os Download typical download Mac Os Download manager at a minimum provides means to recover Mac Os Download from errors without losing the work Mac Os Download already completed, and can optionally split Mac Os Download the file to be Mac Os Download downloaded (or uploaded) into 2 or more segments, which are Mac Os Download then Mac Os Download moved in parallel, Mac Os Download potentially making the process faster within the limits of the available bandwidth. (A few servers are known to block moving files in Mac Os Download parallel segments, on the principle that server capacity should be shared equally by all users.) Multi-source is the name given to files that are downloaded in parallel.
There are several things that some web Mac Os Download browsers are not very good at. That's where Mac Os Download the download managers enter the equation:
Pausing the downloading of large files.
Resuming broken or paused downloads (especially for very large files).
Downloading files Mac Os Download on poor connections.
Downloading several files from a site automatically according Mac Os Download to simple rules (file types, updated Mac Os Download files, etc. - see also Offline Browser).
Automatic recursive downloads (mirroring).
Scheduled downloads (including, automatic hang-up and shutdown).
Searching Mac Os Download for mirror sites, and the handling of Mac Os Download different connections to download the same file more quickly (segmented downloading).
Download managers are useful for active Internet users. For dial-up users, they can automatically dial the internet service provider at night, Mac Os Download when rates or tariffs are usually lower, Mac Os Download download the specified files, and hang-up. Mac Os Download They can record which links the user clicks on during the day, and queue these files for later download. For broadband users, download managers can help download very large files by resuming broken downloads, by limiting the bandwidth used, so that other internet activities Mac Os Download are not affected (slowed) and the server is not overloaded, or by automatically navigating a site and downloading pre-specified content (photo galleries, MP3 collections, etc.) this can also include automatically Mac Os Download downloading whole sites and regularly updating them (see Mirroring).
Many download managers Mac Os Download support Metalink, an XML file Mac Os Download listing mirrors, checksums, and other information useful for downloading.
See below for Mac Os Download some examples of commonly Mac Os Download used Mac Os Download download Mac Os Download managers. Some downloaders are optimized for a certain function. For example, Offline Explorer is designed to download entire websites.
Download managers, such as Go!Zilla, were among Mac Os Download the first Mac Os Download adware applications displaying a banner ad in the user interface.
Related to download managers are two other breeds of Internet programs, file-sharing peer-to-peer applications (Kazaa, Mac Os Download eMule, BitTorrent, Gnutella) Mac Os Download and stream recorders (such as StreamBox VCR).
While download managers Mac Os Download are Mac Os Download designed to give users greater control over downloads, some downloaders are created to give that control to content distributors instead. Some software companies, for example Adobe [1], provide such downloaders for downloading software on their own Mac Os Download site. Presumably this increases reliability and reduces tech support costs to them. A possible reason Mac Os Download is increasing the control over redistribution of their software (even when the software is freeware).In computer technology and telecommunication, on-line and off-line are defined Mac Os Download by Federal Standard 1037C. They are Mac Os Download states or conditions of a "device or equipment" or of "a functional unit". To be considered on-line, a device must be at least one of:
"Under the direct control Mac Os Download of Mac Os Download another device"
"Under the direct control of the system with which Mac Os Download it is Mac Os Download associated"
"Available for immediate use on Mac Os Download demand by the system without human intervention"
"Connected to a system, Mac Os Download and is in Mac Os Download operation"
"Functional Mac Os Download and ready for service"
while a Mac Os Download device that is off-line is not (e.g. Mac Os Download it has "its main power source disconnected Mac Os Download or turned off", and is "off-power").
One Mac Os Download example of a Mac Os Download common use of Mac Os Download these concepts Mac Os Download is Mac Os Download a Mail User Agent that can be instructed to be in either "on-line" or "off-line" states. One such Mac Os Download MUA Mac Os Download is Microsoft Outlook. Mac Os Download When it is "on-line" it will attempt to connect to mail servers (to check for new Mac Os Download mail at regular intervals, Mac Os Download for example), and when it is "off-line" it will not attempt to make any such Mac Os Download connections. The "on-line" or "off-line" state Mac Os Download of the MUA does not necessarily reflect the connection status between Mac Os Download the computer on which it is running and Internet. The user may have the computer itself on-line, connected to Internet via Mac Os Download a cable modem Mac Os Download or an ADSL connection, but may wish for Outlook Mac Os Download to be off-line, so that it makes no attempt to send or to receive messages. Or the computer may be configured to employ a dial-up connection on demand (whenever an Mac Os Download application such as Outlook attempts to make connection to a server), but the connection may be Mac Os Download an expensive telephone call from Mac Os Download the particular location in which the computer currently happens to be Mac Os Download (such as a hotel room) and the user may not wish Outlook to trigger making that call every Mac Os Download 5 or 10 minutes to check for mail.[1]
Another example of the use of these Mac Os Download concepts is in the world of digital Mac Os Download audio technology. A tape recorder, Mac Os Download digital editor, or other device that is "on-line" Mac Os Download is one whose clock is under the control of Mac Os Download the clock of a "synchronization master" device. When the sync master commences playback, the "on-line" device automatically synchronizes itself to the master and commences playing from the Mac Os Download same point in the recording. Whereas a device that is "off-line" uses no external clock reference and relies upon its own internal clock. When a large number of devices are connected to a sync master, it is often Mac Os Download convenient, if one wants to hear just the output of one single device, to take it off-line, because if the device is played Mac Os Download back Mac Os Download on-line all synchronized devices Mac Os Download have to Mac Os Download locate the Mac Os Download playback point and wait for each other to be in Mac Os Download synchronization.[2] (For further related discussion, see MIDI timecode, word sync, Mac Os Download and recording system Mac Os Download synchronization.)
A third example of a Mac Os Download common use of these concepts is a web browser that can be instructed to be in either "on-line" or "off-line" states. The browser only attempts to fetch pages from servers whilst in the "on-line" state. In Mac Os Download the "off-line" state, users can perform offline browsing, Mac Os Download where pages can Mac Os Download be browsed using local copies Mac Os Download of those pages that have previously been downloaded whilst in the "on-line" state. This can be useful when the computer itself is also off-line, with Mac Os Download connection to Internet expensive or impossible. The pages are either downloaded implicitly into the web browser's own cache, as a result of prior on-line browsing by the user, or explicitly by the browser being configured to keep local copies of certain web pages, which it keeps updated when the browser is in the on-line state, either by checking that the local copies are up-to-date Mac Os Download at regular intervals or by checking that the local copies are up-to-date whenever Mac Os Download the browser is switched to the on-line state. Mac Os Download One such web browser capable of being explicitly configured to download pages for offline browsing is Internet Explorer. When pages are added to the "Favourites" list, they can be Mac Os Download marked for being made "available for offline browsing". Mac Os Download Internet Explorer will download to local copies both the marked page and, Mac Os Download optionally, all of Mac Os Download the pages Mac Os Download that it links to. Mac Os Download In Internet Explorer version 6, the level of Mac Os Download direct and indirect links, the maximum amount of local disc space allowed to be consumed, and the schedule on which local copies are checked to see Mac Os Download whether Mac Os Download they are up-to-date, are configurable Mac Os Download for each individual "Favourite" entry.
See also:
Offline browsing known as "Offline favourites" was Mac Os Download removed Mac Os Download as a feature in the most recent version of Internet Explorer 7, which only now supports single web page saving, but not browsing or storing an entire site offline.[citation needed]
Similarly, off-line storage Mac Os Download is computer storage that is not "available for immediate use on demand by the system without Mac Os Download human intervention", i.e it is storage that is off-line.
The ideas of "on-line" and "off-line" have been generalized from computing and telecommunication into the field Mac Os Download of Mac Os Download human interpersonal relationships. The distinction between what is Mac Os Download considered "on-line" and what is considered "off-line" has become a subject of study in the field of sociology.[7]
The distinction between "on-line" and "off-line" is conventionally seen as the distinction between computer-mediated communication Mac Os Download and face-to-face communication Mac Os Download (e.g. face time), respectively. "On-line" is virtuality, and "off-line" is reality (e.g. Mac Os Download real life or meatspace). Slater states that this distinction is "obviously far too simple". To support his Mac Os Download argument that the distinctions in relationships are more complex than Mac Os Download a simple "on-line"/"off-line" dichotomy, he observes that some people draw Mac Os Download no distinction between an "on-line" relationship, such as indulging in cybersex, and an "off-line" relationship, such as being Mac Os Download pen-pals. He also argues that Mac Os Download even the telephone can be regarded as an Mac Os Download "on-line" experience in some circumstances, and that the blurring of the distinctions between the uses Mac Os Download of various technologies (such as PDA and mobile telephone, television and Internet, Mac Os Download and telephone and voice-over-IP) has made it "impossible to use the term 'on-line' meaningfully Mac Os Download in the sense that was employed by the first generation of Internet research".[7]
Slater asserts that there are legal and regulatory pressures to reduce the distinction between "on-line" and "off-line", with a "general tendency to assimilate online to offline and erase the distinction", stressing, however, that this does not mean that on-line relationships are being reduced to pre-existing off-line relationships. He conjectures that Mac Os Download greater legal Mac Os Download status may be assigned to on-line relationships (pointing out that contractual relationships, such as Mac Os Download business transactions, on-line are already seen as just as "real" as their off-line counterparts), although he states it to be hard to imagine courts awarding palimony to people who have had a purely on-line sexual relationship. He also conjectures that an "on-line"/"off-line" distinction may be seen by Mac Os Download people as "rather quaint and not quite comprehensible" within 10 years.[7]
The distinction where "on-line" is seen as Mac Os Download virtuality and "off-line" as reality is sometimes inverted, with "on-line" Mac Os Download concepts Mac Os Download being used to define and to Mac Os Download explain "off-line" activities, rather than (as per the conventions of the desktop metaphor with its desktops, trash cans, folders, and so Mac Os Download forth) the other way around. Several cartoons by The New Yorker have satirized this. One includes Saint Peter asking for a user name and a password before admitting a Mac Os Download man into Heaven. Another Mac Os Download illustrates "the off-line store" where "All items are actual size!", where shoppers may "Take it home as soon as you pay for Mac Os Download it!", and where "Merchandise may be handled prior to purchase!". |
