Governor Limits in Salesforce are the runtime limits enforced by apex runtime engine to write scalable and efficient code.

Because apex runs in a multitenant environment, the Apex runtime engine strictly enforces limits to ensure that runaway Apex code or processes do not monopolize shared resources. If some Apex code exceeds a limit, the associated governor issues a runtime exception that cannot be handled.

Every programming environment imposes its own sets of cost features & constraints.

All programs, services and applications running on the platform run in a multi-tenant environment where resources like memories, networking & database connection are being shared with other program on the platform.

It is very important that platform drives the monopoly of system resources by a single org for which they analyse our code to ensure that we are using best practices & system resources efficiently.

Force.com implements number of governor limits so that applications play nicely with each other.