Is the 737-800 a different plane from the 737 MAX 8?
They are different, yes. The 73H is not the Max 8. The 73H is an -800 with winglets. The -800 has been in service since 1998, with 4,991 deliveries as of February 28, 2019.

See here: What is the difference between Boeing 73G, 73H and 737?


  73H - Boeing 737-800 with winglets (8th letter of the alphabet)


The Max 8's IATA code you'd find on a ticket is 7M8.



For visual identification, see: Is this a 737-800 or 737 MAX 8?