Is cat command read only?

Could you please clarify if the "cat" command in Unix or Linux systems is strictly read-only? I'm asking because I'm trying to understand the limitations and capabilities of this command. Does it only allow users to view the contents of a file or can it also be used to modify or edit files in any way? Additionally, if there are any specific scenarios where the "cat" command can be used to make changes, I'd appreciate it if you could elaborate on those.