How is that Different than that of delete or clean..
If your antivirus encounters an infected file, there are generally three options available: clean, quarantine, or delete. If the wrong option is selected, the results can be catastrophic. And if it's a false positive, such a mishap can be even more frustrating and damaging.
If you imagine it as being an area of your hard disk where possibly-infected files are stored. There is (hopefully) no way this file can (mysteriously) self-activate. In the event that this file attempts to activate or connect to any other file within your hard disk, that step will be monitored and prevented.
Any file has the potential to be a virus. Virus writers can create a file that looks and behaves like any file you can imagine. For example, NOTEPAD is commonly found on Windows PCs. There have been viruses which look and appear to act like the genuine NOTEPAD programme, but they actually contain malicious software. In this case, NOTEPAD is chosen because people recognise the name and function of this programme, so they overlook it.
Quarantine would mean it detected it as one but it may not be so you take action on it.
Delete of course is deletion. Gone.
Clean is keep the file but get rid of any issues.
The file is not touched, and is moved to an area where it wont affect the PC.
Delete – deletes the file. Clean – removes the virus.
The virus is basically jailed