UID, GID, and Sticky Bit in WinSCP?

[Steve32]

My FTP client (WinSCP), when connected to my hosting account then showing a fourth permission "characteristic" for Owner, Group, and Other:

Owner has a "Set UID" option
Group has a "Set GID" option
Other has a "Sticky Bit" option

Can anyone explain me what these file permission characteristics mean and what the appropriate settings for each option?.

 

[Hassan]

These are special permissions. Set UID and Set GID are used with executable files. They grant the user, who executes the file, permissions of file owner or group, respectively. Sticky bit for executable files makes the kernel keep the memory image of the process after it has terminated, in order to avoid the overhead of reloading it when it is re-invoked. Sticky bit for directories ensures that only the owner of a file can remove or delete the file or directory.