The User Preferences screen (accessed with the link My Prefs on each page) presents two tabs for the user:

Preferences#

Name

This is your "Wiki" Name and is usually set to the Full Name (from the profile tab, below) without spaces

Editor

This is a preference setting for the editor to be used when you are creating or modifying wiki pages.

Section Editing

If toggled, a link will be placed beside each header, if you are allowed to edit that page.

Skin

This shows the different styles that the wiki may be shown to you. Skins are defined in the templates directory.

Language

This controls the language of the wiki - not the language that the pages are presented in.

Favorites Style

This controls which side of the screen the menu is presented on (default is Left side)

Time Format

This controls the format that dates are presented in page history screens

Time Zone

This is your time zone, if it is different from where the server is set.

Clear User Preferences

Pressing this button will clear the cookies used to remember your settings.

Profile Tab#

Login Name

This is the user name that is used in the login screen.

Password

Your password. It stored, hashed, using the SHA-1 hashing algorithm

Name

This is your Full Name, and is used by an administrator to provide membership in Groups or access control lists

Email Address

Your email address, in case you need your password reset

Roles

This shows the roles that you have, for security purposes (usually All and Authenticated)

Groups

This shows the groups that your user is a member of