Mostly. Each region is slightly different in how they operate, but they all have a regular season consisting of teams going against each other in an attempt to get high placements (higher placement = higher seeding in playoffs). Once the regular season is done, the region goes into their playoffs which varies greatly from region to region. In EU and NA, it's a 6 team single elimination bracket with a third place match, in Korea it's a 5 man gauntlet run with a Bo3 wildcard match, in the LMS it's a 4 man gauntlet run*, in China they turn everything on it's head and do a slanted double gauntlet run (two teams in the first round get a free win for higher seeding, then proceed to continue a normal gauntlet until the finals) with a third place match.
The winners of the region's playoffs continue on to the World Championships, but wait! There's more! Worlds isn't just MSI, it includes 2nd and 3rd seeds for most regions (except from the LMS and IWC). The second seed is usually determined through champion points which are rewarded at the end of the Spring and Summer Splits based on how a team ended (this also varies from region to region), the team with the most that didn't win the Summer playoffs becomes the region's second seed.
Now you may be wondering, what about the third seed? Well, the remaining teams are seeded into a 4 man gauntlet(based on how many champion points they've earned**) with the winner proceeding as the third seed to Worlds.
The IWC seeds are decided at IWCQ which will be inviting the top teams from each of the wildcard regions (Turkey, Brazil, Latin America North & South, Japan, Eastern Europe, Australia, and Southeast Asia), this is the first year they've done the IWCQ (before they had two different tournaments with the regions split up between the two), so I can only assume it'll be similar to the IWCI with a double round robin with the top 4 teams moving on to a Knockout stage with the winner taking the 1st IWC seed, and the runner-up taking the 2nd IWC seed.
Then we have the Pools for Worlds and the drawing. The top 4 seeds are placed in Pool 1 (There are technically 6 top seeds though, but the regions that made it into the knockout stage at MSI secured the top 4, so NA, KR, CN, and TW). Pool 2 consists of 8 teams also slightly varying on MSI performance (since EU failed to place in the top 4, they have their 1st and second seed in Pool 2, NA has their 2nd seed, CN and KR have their 2nd and 3rd seeds, and TW has their 2nd seed). Pool 3 is made up of NA's 3rd seed, EU's 3rd seed, and the 2 IWC seeds (usually). These Pools are then drawn from into 4 groups with teams from the same regions unable to be placed in the same group.
The group stage consists of a double round robin of Bo1s with the top 2 teams from each group moving on to the Knockout Stage. Here's where I'm a little hazy myself: The knockout stage is I think semi-randomly seeded with #1 teams from the group stage facing only #2 teams from the group stage. It then proceeds as a normal 8 man bracket usually does with the winner being crowned the Champions.
*- A 4 man gauntlet consists of 3 rounds, with the 3rd place and 4th place facing each other at the bottom, the winner faces 2nd place in round 2, the winner of that faces 1st place in round 3, with the winner of that being the winner of the playoffs. Korea uses a wild card match where 4th and 5th place face each other in a Bo3 in the first round, then it's Bo5 through the rest of the tournament with the expected seeding for each round. The Chinese slanted gauntlet is basically two gauntlets with the winner of each facing each other in the finals, and the second place of each gauntlet facing each other in a third place match.
**- TW might be slightly different in how they decide their seeds with them only earning champion points in Spring and Summer playoffs to decide seeding for their regional qualifiers, the winner then receives the 1st seed for Worlds, with the second place team getting the 2nd seed.