There are several charging modes for a Leaf. The generic terms are L1, L2 and L3. On a Leaf, L1 = 120V, L2 =240V and L3 = CHAdeMO.
L1 is slowest and L3 is fastest. L3 (CHAdeMO) requires a special, very expensive charger and is not something that you would put in your house. There are CHAdeMO stations around but they tend to be expensive to use, although some are free (mostly Nissan dealers).
L1 (120V) is slow but it can use an inexpensive EVSE (electric vehicle service equipment) cable. An EVSE is really just a 'smart' extension cord that plugs into a wall receptacle and supplies either 120V or 240V to your Leaf. In this case the charger is actually inside the Leaf.
L2 (240V) is faster than L1 but slower than L3. This is also used by many people at home but you need an appropriate 240V receptacle to plug it into.
Besides voltage, the current draw is also very important. The power delivered to charge the car is voltage * current (watts). Nearly all 120V (L1) chargers will use at most 12A so they can be plugged into any normal 120V outlet in your house. When using 240V (L2) there are various current ratings available but the circuit and receptacle you use must be capable of supplying the necessary current.
Finally, not every Leaf can use CHAdeMO. Some models do not have a CHAdeMO plug so they cannot use L3. There are also some difference between the charger inside the Leaf when using L1 or L2. Some Leafs can accept up to 6.6kW while some only accept up to 3.3kW.
I know this is a lot of information to digest all at once but if you have a Leaf model or year/trim that you are considering, please ask about that and you can get a much better idea of how fast it can charge.