Being on the team benefits your personal goals and ambitions. Being a teammate benefits the goals and ambitions of your team and your teammates.
Being on the team can make you a bystander. Teammates intervene in the lives and actions of their teammates.
Being on the team involves personal effort. Being a teammate involves the efforts of every player.
Being on the team means doing what is asked of you. Being a teammate is doing whatever is needed for the team to succeed.
Being on the team can involve blaming others and making excuses. Being a teammate involves accepting responsibility, accountability, and ownership of the team's problems.
Being on the team makes you "me-optic," asking what's in it for me? Being a teammate makes you "we-optic," asking what's in it for us?
Sometimes players on the team are drawn together by common interests; teammates are drawn together by a common mission.
Sometimes players on a team like one another; teammates respect each other.
Sometimes players on a team bond together because of a shared background or compatible personalities; teammates bond together because they recognize every player is needed to accomplish the goal of the team.
Sometimes players on a team are energized by emotions; teammates energize one another out of commitment.
From "Inside Out Coaching" by Joe Ehrmann