What hard forks were implemented, and what functionalities did they introduce?
Hard forks in Cardano do not signify division and differences within the ecosystem. On the contrary, they define a specific and collectively agreed-upon exact time (slot) when all nodes switch from the current era to a new one, applying new functions, validation rules, or parameter values. All stake pool operators need to install the upgrade, and they also have a say and must agree to it. A Cardano hard fork is, therefore, not a separation but a precise collective evolution.
Note that some hard forks, particularly Byron and Shelley, transitioned through a series of updates and may not have a single specific transaction id associated with them. For the others, the provided transaction ids correspond to significant parameter updates leading to the hard forks.