Activity completion
From MoodleDocs
Activity completion is a setting which, when enabled, allows the teacher to set completion criteria against an activity. A check(tick) appears against the activity, and this changes style when the activity has been completed. The activity may be classed as completed automatically if the student has fulfilled certain tasks, or the student may be allowed to mark it complete manually.
See the links on the right Activity Completion Settings and Using Activity completion for more information
NOTE: There is also an Activity completion condition in the Restrict Access settings of an activity when using Conditional activities However, it is possible to track activity completion without using Conditional activities
