FTP (File Transfer Protocol) is the Internet in an old protocol, FTP server and file server functions similar, it can allow users to download the client from the server or upload files.
FTP server using a client / server mode of operation, using the TCP protocol connection between the client and the server.
User isolation is an important feature in Windows Server 2008 R2 system FTP services. If you do not isolate users, then all users after login FTP site, the default will be directed to the home directory of the FTP site, and see the same content. By isolating users, allows users to have their exclusive catalog, this time the user logs on the FTP site, will be directed to this exclusive directory, and can be limited to its exclusive directory, which is not exclusive to switch to another user directory, thus only view or modify files within their own exclusive directory. For anonymous users, you can set a public directory, if it is used as an anonymous user login to see the same public content.
Open "FTP user isolation", the system default is not isolated from the user, all users are automatically directed to the FTP root directory [] in IIS Manager. To enable user quarantine, you can choose "User name directory (disable global virtual directories)," below, then click the "Apply" link to the right.
Then we need to login FTP users to have the exclusive authority to set directory. User-specific directory must be located in a subdirectory under the FTP site home directory, it can be a physical directory, or virtual directory.
According to different types of users, an exclusive directory has the following types:
LocalUser \ Username: localuser folder is a local user-specific folders, and user name is the name of a local user. Local users need to log into the FTP site every need of each to create a new subfolder under the exclusive localuser folder, the folder name and the user needs the same name.
Localuser \ public: When users log on anonymously, will be directed to a public folder.
Domain Name \ User Name: If the user is to log on the FTP site using the domain user account, then you first need a dedicated folder for the domain was built, the folder name to be the same as the NetBIOS domain name; then under this folder for every It requires domain user logs on the FTP site, each a unique new sub-folder, the folder name and the same user name.
Here we coolpen local user admin, domain user \ lisi, anonymous user to set an example for user isolation. Under the FTP site's home directory need to create the following folder: 
place the appropriate test files in each folder separately, then the client with a different user logged in, you can find are directed to a different exclusive folder.
If you need to assign permissions to users to upload, the same as the previous setting, you first need to add authorization rules "FTP authorization rules", and then set NTFS permissions user-specific directory.
In fact, if you use FTP services to the Web site for updates, it is not possible on the Web server for each site have established a corresponding FTP site. If using user isolation, you only need to set up an FTP site, and then create a home directory for each Web site in the FTP home directory, then create the appropriate user account to the server, so you can only use an FTP site on update on all Web sites.