A Per-seat license is a software license based on the number of individual users who have access to the software. For example 50-user per-seat license would mean that up to 50 individually named users can access the program (compare named user licensing[1]). Per seat licensing is administered by providing user-level security to the directory containing the program. The alternative is a concurrent user license, based on the number of simultaneous users—regardless of which individuals they are—accessing the program. It typically deals with software running in the server where users connect via the network. For example, in a 50-user concurrent use license, after 50 users are logged on to the program, the 51st user is blocked. When any one of the first 50 logs off, the next person can log on. Concurrent licensing can be managed by the application itself or via independent software metering tools.
Per-seat licensing is common for products used by specialised professionals in industrial settings. In addition to computer programming, typical examples include chemists[2], molecular biologists [3], geographers,[4] and designers.[5]