uptime command is a measure of system reliability, expressed as the percentage of time a machine, typically a computer.

In man page the describe it
- uptime – Tell how long the system has been running.
- man uptime – More details information.
Uptime command in Linux with Examples
$ uptime
Conclusion
uptime commandis the simple the command in Linux. It is the most popular in use terminal Linux for Tell how long the system has been running.