Communication in its most general form, is conveying a message from a messenger through a medium to the intended receiver. In the context of a team, effective communication would essentially mean enabling other team members to perceive or understand how the messenger intended his message to be regarded. However, both the sender and receiver have equally important roles to play in order for that to happen. The sender on his part has to take the background information of his audience into consideration before paraphrasing his message according to their prior knowledge of the subject. The listener also has to be attentive in order to decode most accurately what the intended message is.
Teamwork, on the other hand is a word that is full of nuances. To a layman, it may simply means working together in a team. However, I believe it is but a fleeting explanation. It should encompass the synergy of the different behavior, attitude & mindset of each individual person in the team. Teamwork should also comprise of cooperation, cohesion, trust and rapport between each and every member, all of which are built upon via effective communication. Lacking in any of the aforementioned qualities would reduce a team to no more than a mere group where there is a lack of common goal and everyone is for himself.
Hence, communication and teamwork are correlated interdependent elements that are vital to the functioning of a team. Communication can be seen as the link between every team personnel whereas teamwork is hinged on the comprehensive effort of the team as there is no one man show in a team. I personally believe that only when the two components coexist in a team, will it be a force to be reckoned with.