There are many ways to remote into another computer and various reasons to do so. By far, the combination that happens most of the time in my daily life is remoting into another computer to help someone. I used an older version of TeamViewer because it was the one our institution once licensed. We moved to using Zoom instead, which has some significant drawbacks when used this way. Finally, the institution moved to using MS Teams for most purposes.
TeamViewer
Zoom
MS Teams (part of MS 365)
Remote Desktop Connection (built into Windows)
Quick Assist (built into Windows)
Internet Service Layer (ISL) is commercially available through ISLonline.com
LogMeIn
RAdmin
VNC
Synergy