What is the number of people present at a particular place or event called?

Attendance is the concept of people, individually or as a group, appearing at a location for a previously scheduled event. Measuring attendance is a significant concern for many organizations, which can use such information to gauge the effectiveness of their efforts and to plan for future efforts.

In both classroom settings and workplaces, attendance may be mandatory. Poor attendance by a student in a class may affect their grades or other evaluations. Poor attendance may also reflect problems in a student's personal situation, and is an indicator that "students are not developing the knowledge and skills needed for later success". For students in elementary school and high school, laws may require compulsory attendance, while students at higher levels of education may be penalized by professors or the institution for lack of attendance.

Attendance control has traditionally been approached using time clocks, timesheets, and time tracking software, but attendance management goes beyond this to provide a working environment which maximizes and motivates employee attendance. Recently it has become possible to collect attendance data automatically through using real-time location systems, which also allow for cross-linking between attendance data and performance.