By using Quota Template you can determine how much data a site collection can hold. Site collection quota template is applied to entire site collection including all the sub sites created under it.

Step-by-step process to create Quota Template in SharePoint 2013

Go to Central Administration >> Application Management >> Specify quota templates

Required values for Quota Template

Enter all the values as shown in Screenshot and description below

1. Template Name: Enter the name of the template you want to create. At the time of selecting quota template, this name will be displayed in drop down.
2. Storage Limit Values: Limit site storage to a maximum of: Enter the size in Megabytes (MB). This is the maximum size a site collection can grow up to.
3. Storage Limit Values: Send warning E-mail when Site Collection storage reaches:Enter the size in Megabytes (MB).

   If the site collection reaches to this warning limit, a mail will be sent to Site Collection Administrator.

   You need to make sure out going email is configured to use this facility.

   You also need to make sure: The Disk Quota Warning timer job is running.

4. Sandboxed Solutions With Code Limits: Limit maximum usage per day to:Specify the maximum daily usage in points.

   Point is a relative measurement of the resource usage, e.g. CPU cycles, Page faults, Memory

5. Sandboxed Solutions With Code Limits: Send warning e-mail when usage per day reaches: If the usage reaches the warning limit, a mail will be sent to Site Collection Administrator. You need to make sure out going email is configured to use this facility.
6. Press OK. New Quota Template will be created.

Conclusion:

We went through all aspects of creating Quota Template in SharePoint. If used, this feature can be very useful in saving server size.