Virtually all 110 volt outlets look the same. They have two vertical slots placed side by side, one of which may be larger than the other if the outlet is polarized. There may also be a third semicircular slot forming a triangle with the other two. It’s for a ground pin.
There is no such commonality among 220-volt outlets. The pin configuration depends on the current rating of the breaker controlling the circuit. However, there are a number of key differences between a 110 outlet and a 220 outlet:
The 220 outlet is larger, and it’s usually round and black or dark brown, not white.
It can have three slots or four. Four-slot outlets have a ground wire. One or more of the slots is set horizontally or at an angle.
There is only one outlet, unlike 110 outlets, which are almost always installed in pairs called duplexes.