Both of these words refer to people who work at a company - but staff is always singular and uncountable - it describes the entire group of workers as one thing. Employees is plural and countable - it describes the collection of individual workers.
The entire staff was happy about the extra day off.
All the employees were happy about the extra day off.
Note that "staff" takes the singular verb was, and "employees" takes the plural verb were.
Whenever you use a specific number, use employees or staff members:
Your best bet is to try to swim over the wave before it breaks. If this is not possible though then you need to extend your arms and legs away from yourself to spread the impact and keep yourself from being thrust deep into the water. Take a deep breath and wait until the turbulence subsides. Youll get tossed around but try to stay oriented and dont panic. Get back to the surface quickly, breathe, and reassess the situation because you may have to repeat.