Example is an account created to be used in examples where you don't want to name a particular user.

User:Place holder is a similar account, used when you intend to replace the user name with an actual user later.

Free images uploaded to Wikimedia Commons or Wikipedia may be included in user pages as well as articles. Here is an example image you can use for testing purposes.

 
Test pattern

Users can create subpages in their own userspace, for purposes such as drafting articles. Below is an example of a subpage:

Users can talk with other users: