There are 2 kinds of server systems that are used in Counter-Strike Global Offensive which are:
1. 64 Tick Servers
2. 128 Tick Servers
These are the only 2 sorts of servers used in csgo, they are used in community servers, eSports tournaments, competitive match-making, War games, Casual, Deathmatch, and every other server or mode you can possibly think of, and they are used in offline mode as well. Both have their Pros and Cons and both are used varying upon different events at different scenarios.
64 Tick Servers.
64 Tick servers are the servers that are mainly used in CSGO game modes, for example, every game mode in csgo either is it competitive servers or deathmatch, casual, or war games. Community servers are 64 tick servers as well but not all of them, if there are 68% 128 tick servers then there are 32% 64 Tick servers. Servers that run on 64 Tick Function have a bit of inaccuracy in sense of aim and velocity speed for bunny hopping (Bhopping) or Strafing in servers to develop movement speed while playing, not mostly but sometimes crosshair placement is right but shot misses due to server ticking but these servers are cheap and easy to set up but as people do recommend these servers as well but most of the server hosters do not host 64 tick-based servers due to the cons i have listed above and their only pro is that they are affordable.
128 Tick Servers.
128 tick servers are mostly used in community servers and professional platforms like ESL, ESEA, Faceit, and they are also used in Major and Minor tournaments that are hosted by Valve or these platforms. They are not much but are a bit more expensive than 64 tick servers because they are better than performance and they do not lack inaccuracy of aim and they have accurate velocity for Strafing or Bunny Hopping (Bhopping) but a little more cost they do really perform at their best and in most of the cases people host 128 tick servers over 64 tick even in community servers most of the servers are 128 tick-based servers.
Both 64 servers and 128 ticks are the only servers used by the community and valve itself, although, in community servers both 64 and 128 tick servers can be added or can come with modifications or without any of sort modification, modifications like skin changing feature or you can say skin applier, gloves, and any other in-game equipable item or it can be a retake server to enjoy retake games even though retakes are now an official mode and bunny hopping enabled servers which makes bunnyhopping literally easy to do because of the gravity and velocity settings applied to the servers and people do prefer using these features or modification to make the game more interesting for themselves and other users to come and play the game to enjoy it with their friends. These servers in the community are known mostly by their titles for example csgo surf servers or csgo bhop servers etc.