what is difference between data filters activity and SQL activity?

Apply a data filter to create a group or data extension containing records that meet a set of criteria. For example, use a filter activity in Automation Studio to sort out subscribers from a larger subscriber list.

• Data filters are created in Email Studio. Create the data filter you plan to use in the filter activity before configuring the activity.
• If you select a filter that is based on profile attributes, select the list to segment with the filter. Provide a name for the group that contains the resulting segment.