The difference between the two items in the subject (when used to retrieve data from a datasource), depends on what you want to do with the items. Examples are as follows:
Text='<%# Bind(“FirstName”) %>’
Text='<%# Eval(“FirstName”) %>’

If all you want to do is display the data directly from the data source (one way databinding), you can just use ‘EVAL’.

However, for 2 way databinding (when you use the datasource and want to update/insert, etc.), you want to use ‘BIND’.