How does softwaredevelopment work in a company?

How does software development actually work in a company? Multiple people are working on software, maybe on different features. They push their changes to the respective file/sub-folder of the main directory/branch(?), how does the fixing of issues related to, for example, the other's feature work? If it's between 2 people then surely it wouldnt be too difficult, but what about in a team of 10 people? how would they stay on updated code since I'm guessing that some developers are faster done with their features than others.

Idk if it works like this, but is there an IDE where all devs are connected to some server hosting the main repo, and the code from the other developers auto-update in real time? or is that completely bonkers?

Hope this makes sense, it's a shower thought that popped into my head.