What is primary attack and secondary attack?

[Veilgn]

I am a wizard who soon play a summoner. And I must spend evolution. But I find primary attack upgrades and secondary upgrades.

Since I can put more than once. I will put almost all evo tentecles let say 4 times.

Is that mean after primary attack. Secondary attack go as well ?

I never play warrior. And so I dont know this and cant find the wiki.

[MeanMutton]

This explains it: Natural Attacks