When designing, you need to take into account the user’s context. Location is a commonly understood contextual factor—are you designing for someone on the go or for someone sitting at a desk? But there are other things to consider, including the time available with the user, her emotional state, the device she is using, the people who influence her, and more.
All these factors help you understand the user’s behavior. Once you have insight into that, you can prepare a design that maximizes user experience. For example, the emotional state of a user would impact how patient or impatient she might be when interacting with the user interface of your product or service, so you’d want to design with that in mind.