Discrete Picking or Single order Picking
Cluster picking is majorly location-driven where in SKUs for multiple orders would be picked from one particular location
Batch picking is an order picking protocol that calls for the picker to compile a batch of the orders by picking from a single SKU or one SKU at a time.
In zone picking, the entire picking area is divided into different zones and each picker is assigned to a particular zone.
Grouping of orders into waves is the first step in wave picking, it can be done on a small number of orders like 4 or 5 or on a large number of orders, like hundreds, depending on the order volume & the shipping routes/schedules.