How to do collaborate Google docs.?

Hi all experts,

I recently started working Google docs online, as I have to create some excel sheets presentation and submit to the client. I am working with a team, all are working on the same excel sheet. Sometimes, its create problem as all can edit the Google doc at a time and others may not knowing what editing has been done by other. I have heard about collaborate Google docs that will remove this problem, can anyone educate me how to start collaborate Google docs feature and how to implement it.