Some people use the word team to say that they work with other people together. For instance in the traditional big shop, the Architect works with the developers and testers. Everyone has their pigeon holed tasks.
In our small team, team means that anyone is capable of doing the job. While I may be responsible for overall direction as team lead, anyone can do all of the tasks. From working to manage the work, the needed documentation/status reports, business analysis, development and testing. This arrangement has been very beneficial for us in terms of integrating new people and coping while people are out a week at a time.
Because everyone can do the work doesn't mean there aren't specialities. Quite the contrary. A really good team will be a blend of people with different backgrounds, skills and strengths which complement each other. A shared vision with a project that has been broken down into achievable goals helps to focus the team on the work.
Another very important aspect of the team is respectful communication and understanding. Feedback is important. In a functional team the members let each other know when they are not understanding the other persons view or actions as well as when things are going well. Don't delay the feedback.