The phrase "to give back" means to return something that was previously taken or borrowed, often with an intention to make amends for something one has received. Full definition
Publicity and / or supplies of magazines for charitable events are provided to these organizations as a means of giving back in appreciation of the efforts put forth by these fine organizations. (awlfc.org)
By giving some back story to your interests, they have a better understanding of who you are and what you really enjoy doing. (maturedating.com)