You can define a 'Maximum Number of Form Entries'. This is the maximum total number of entries that a form can be submitted. E.g. A survey or competition that will accept only a set number of responses.

You can use Maximum Number of Entries in combination with a Submission Limit. A Submission limit defines the number of submission from the same email address.

EXAMPLE 

You would like to run a survey and obtain the results from 100 visitors.

You would set the Submission Limit to 1 per Email Address and the Maximum Number of Entries to 100