In Linux, a process is a program or task that is executing on the system. Each process has a unique identifier called the process ID (PID). You can view the running processes on your system with the ps command.

The ps command provides a snapshot of the current running processes. By default, ps only shows the processes running for the current user in a list format.

Here's an example output of the ps command:

The columns in the output represent:

• PID: The process ID of the process.
• TTY: The terminal associated with the process.
• TIME: The total CPU time the process has used.
• CMD: The name of the command that started the process.

You can also use the top command to view the running processes on your system. The top command provides a dynamic real-time view of the running processes and their resource usage. To exit the top command, press the "q" key.

Here's an example output of the top command:

The columns in the output represent:

• PID: The process ID of the process.
• USER: The user who started the process.
• PR: The priority of the process.
• NI: The nice value of the process.
• VIRT: The total virtual memory used by the process.
• RES: The resident memory used by the process.
• SHR: The shared memory used by the process