Context is a concept that is frequently used by people who use the GTD methodology. It allows you to assign tasks to certain contexts in which they must be completed. For example, 'work', 'home', and 'shopping' are some commonly used contexts. The idea behind contexts is that it isn't productive to be reminded about tasks from one context when you are in another context. In other words, when you are at work, you don't want to see all your tasks that can only be completed at home.