Every member of a space will get a member profile that inherits information from their user profile, which you can view by going to the Members section and selecting their name. This contains standard information such as when they joined the space, how active they have been and what recent activities they carried out in the space. However, you can also customise this profile with extra information that you want members to share by adding your own profile headings.
In the space go to Settings and choose the Profile headings option. Here you will find a list of all the headings under which members can enter information to be shown in their profile. To add a new heading select the New button.
There are a number of different styles of headings. The Multiple choice type lets users select a value from a number of choices, for example what title they have in a team. The Single line of text type is useful for things like phone numbers. The Rich text area type is good for longer descriptions and also allows external content to be embedded, for example a personal Google calendar. All the types are described in the help system.
Some information can be private, viewable only by users with the right to edit other users. Some may be set only by space administrators, for example if you wanted only an administrator to set the title that a member has in a team. For multiple choice and single line of text heading types you can also opt to have the information displayed on the member index page.
You can add a section to the space home page that shows all the members with a particular multiple choice profile heading and value. To do this see How can I show profile information from certain members on the space home page?