Seascape generations start with zero and move up as the platform advances. More games are created, or have later seasons, and the in-game rewards will vary by season. Later games and seasons will give higher generation levels (gen 1, gen 2, etc). As a general rule of thumb, the lower the generation, the higher the value of the Scape. So the earlier you are in on the action, the more valuable your Scape is.
The current generation of Scapes for Season 2 of Profit Circus, NFT Brawl, and Staking Saloon is Generation. These Scapes have half the power of the previous generation. Currently, there are no generation-based combinations for Staking Saloon, so cross generational scapes will still give the same rewards as listed here.