What is “every” in Quote/Contract?

Every is used when you create a quote with a recurring service. 
For example, suppose you wish to create a service quote for a 1-year duration with a service frequency of every 3 months. In that case, you can select “Month” from the dropdown menu, input “3” into the text box, and check the “every” checkbox to indicate the frequency as shown in the picture below.
Note: Please note that this option is only available in “Recurring” quotes
These are the steps for every:

1. Go to Quotes
2. Click NEW button
3. Set Duration

4.Set Frequency in items

5.Enable Every