Work is a necessary activity that most people must engage in for much of their lives to support themselves and their families; however, motivation and job satisfaction vary for both workers and specific types of work. Some workers are motivated by a sense of accomplishment, some by helping others, and others by personal fulfilment. Some people work because it helps them keep busy, or feel useful, or because it allows them to meet a lot of people, or because it provides opportunities to make new friends. Others like to work because they like doing a variety of tasks, experiencing new things, or because it offers the opportunity for improvement and learning. And some people like to work because it gives them power or influence over others.