MAME stands for Multiple Arcade Machine Emulator. When used in conjunction with an arcade game"s data files (ROMs), MAME will more or less faithfully reproduce that game on a PC. MAME can currently emulate over 2600 unique (and over 4600 in total) classic arcade video games from the three decades of video games - "70s, "80s and "90s, and some from the current millennium.
The ROM images that MAME utilizes are "dumped" from arcade games" original circuit-board ROM chips. MAME becomes the "hardware" for the games, taking the place of their original CPUs and support chips. Therefore, these games are NOT simulations, but the actual, original games that appeared in arcades.