A feature is a smaller part of the product that delivers a value to your customers by meeting their requirements. Most common way to deliver value by a feature is to solve a client's problem or do something which can help them in achieving their goals.
In MyProductHub we have Ideas (a Feature or a set of features) which can be arranged as Themes. Each Idea is divided into smaller iterations which can be mapped to a specific user story. Iterations can further be divided into user stories if required to handle it in smaller pieces.