The Maverick 88 is a less costly to manufacture, simplified version of the pump action, 12 gauge Mossberg 500 shotgun.
Factory Maverick 88's feature a black, synthetic only stock and forearm, cylinder bore (although chokes are available), and cross-bolt safety. Accessories are mostly compatible with the Mossberg 500.
The Maverick line of shotguns are assembled in Eagle Pass, Texas using manufactured parts, mainly from Mexico; which contributes to their relatively lower price in comparison to the Mossberg 500 series of shotguns which is assembled and manufactured in the USA.
The trigger groups will not interchange between Maverick 88 and Mossberg 500 guns, but the majority of other parts including barrels, stocks, and shell magazines will (the barrel and magazines must be the same length).
Maverick 88 shotguns feature a trigger guard mounted cross-bolt safety as opposed to a top tang safety, which is used on the Mossberg 500 series.
Early Model 88's were equipped with a single slide rail, but this was updated to a dual slide rail in 1990.
Maverick 88's are factory finished with steel bluing only, whereas Mossberg 500's have factory blued, stainless steel or parkerized (receiver/barrel/magazine) options.
There are two basic models of the 88, the 88 field and the 88 security. The 88 field comes with a longer 28" vent-rib barrel, whereas the security comes with an 18-1/2" (6 round capacity) or 20" (8 round capacity) non-vent-rib barrel. The 88's have a cartridge capacity of 6 or 8 shots and cannot have their magazines easily extended without machining.
I bought an 88, saved some money rather than get the 500... It's still assembled in the USA.