- Info:

- Profiles define access to objects and their fields.

- For instance if user can create, read, update or delete records of that Object.

- Or if it can create, read, edit or delete fields of that Object.

- When you edit a Profile you get a list of all Objects and for each you can define CRUD permissions.

- Profiles are then assigned to users.


- Additional Info:

- Profile defines accessibility on the API level.

- If field is only hidden from page layout it can still be accessed in other ways like through API.