Monero used to have 2 network upgrades (hard forks) a year, but this is not the case anymore. The choice of the biannual hard forks was taken in order to be able to introduce important consensus changes, which added privacy features and network-wide improvements (For example @bulletproofs and CLSAG both required a hard fork) and avoid the ossification of the protocol. Recently, the biannual hard forks included changes to the PoW algorithm, to preserve ASIC-resistance.
Monero je imao 2 nadogradnje mreže (hard fork-a) godišnje, ali to više nije slučaj. Izbor u korist dva hard forka godišnje napravljen je kako bi se mogle napraviti važne promene u algoritmu konsenzusa, dodale funkcije privatnosti kao i poboljšanja na mrežnom nivou (na primer, primena @bulletproofs i CLSAG zahtevala je hard fork), kao i da bi se izbeglo zastarevanje protokola. U novije vreme, dvogodišnji hard forkovi su promenili algoritam dokaza o radu (PoW) da bi se odupreli rudarstvu putem ASIC-a.