The Recent activity category compiles the latest activities for your projects. This includes any new entry on a source or any new comment [HP1] added by taggers on entries of your projects. You will find the name of the project and the name of the person tagging an entry or sharing a comment on the project.
By clicking on the entry or entry comment, you will be able to access the specific entry or the specific comment. In case it is a comment, you will then be able to answer the comment by clicking on the speech bubble icon.