"Can" is one of the most commonly used modal verbs in English.
It can be used to express ability or opportunity, to request or offer permission, and to show possibility or impossibility.
Examples:
I can ride a horse. ability
We can stay with my brother when we are in Paris. opportunity
She cannot stay out after 10 PM. permission
Can you hand me the stapler? request
Any child can grow up to be president. possibility