Under Settings > Advanced > Workflow you can turn the 1-click approval setting on and off for your company by checking the box:

... then your coworkers always have to give an extra confirmation, and therefore an extra click, after they click Approve on a document:

... then your coworkers can approve documents with a single click, without confirming the approval. In other words, a coworker approves a document as soon as they click the Approve button.