![[Pasted image 20250206062727.png|apiserver-arch]]
### Main points
- the only kubernetes [[Components|component]] that can be **horizontally scaled** be [[#active-active|active-actively]] used.
- each component that wants to connect to another component, it should talk to `apiserver`.
- authentication and authorisation is done by apiserver.
#### active-active
When you scale out a service, if they are *active-active*, both of the are operational and working at the same time. On the other hand, if they are *active-passive*, only if the active one goes out, the passive one will start working.