There you will see something like this:

This particular document has version control enabled. You'll notice several new additions.

Firstly, there is a 'Check Out' button at the top of the record. This enables the currently logged-in user to check out the record. This also checks out any files associates with the record, and locks them from being edited.

When the record is checked out the following message will appear:

...informing you that only the current user will be able to edit the record while it is checked out.

At this point the user who checked out the record won't notice any difference and can freely edit the record. Other users, however, will be given an error if they attempt to edit the record, explaining that the record is already checked out.

When the record is checked out, the button at the top of the screen will switch to 'Check In'. Clicking this will bring up a new form to fill in:

This form allows you to describe the changes that were made to the record. These will be included in the version entry for this record.

Once submitted, the lock is released on the record and it can be checked out by another user.

If the record is attempted to be edited while it is not checked out, an error will be displayed to the effect of: “This item is version controlled and cannot be edited without first being checked-out.”.

The new version of the record will then be seen in the version list at the bottom of the record, or by going to the Versions drilldown.

The version entry contains some key bits of information: 

Version Number
This is a unique number identifying this version. It increments each time a document is checked in. 

Date Checked Out
This is the date that this version was checked out. 

Date Checked In
This is the date that this version was checked back in. 

Changes Made By
This is a link to the user that checked out, made changes and checked in the record and associated files. 

Comments 
This holds any comments that were entered when the item was checked in. 

Details
This field shows a detailed description of what was changed in the actual record between versions. 

File1, File2, File3, File4, File5
These contain links to any files that were associated with the record. 

On each version there will be a “Rollback to This Version” button. Clicking this enables you to revert the version of a record to an earlier date.