IPSec vs IKEv2

Hello,

I am a high school junior working on my submission for a network design competition (don't have any significant certs yet only an MTA-hopefully I will have my CCNA by the end of high school as I have been self teaching myself networking). Instead of going for an Ethernet Private Line or leased line to connect up sites for this project, I figured using IPSec would be much more practical, cost efficient, and scalable. When I was doing some research, I stumbled upon something called IKEv2. Could someone clarify how IKEv2 is different from IPSec and when to use one over the other?

Thanks!