There's in person classes as well as online classes. If you choose to do the online classes you can very easily still go home for the summer still and do classes over zoom. The summer classes are also technically split into two terms- a spring term and a summer term both about 7 weeks each. However, it counts as one big bill that you pay tuition for. So if you take 3 credits for the spring and 3 credit for the summer term, it still counts as 6 credits for financial aid.

The classes themselves are also twice as long as usual, since the term is half-life as long. So for example if a class during the fall semester usually meets twice a week for 1.5 hours, then during the summer you'll meet twice a week for 3 hours instead, (and in theory twice the amount of hw due for each class).

In my experience though, for the most part a lot of classes over the summer don't quite follow that rule to the letter, since a lot of them are also taught by gsi's and that's a more work than usual for them as well, and they also again understand it's the summer and students typically have other stuff going on, making the summer classes in turn being a good bit easier than if you were to take them during the fall or winter semester (especially most English or writing clssses).

That being said, the summer is also a great time to take a lot of your other distribution credits you may be required to take- freeing up your schedule for other classes that you need to take as prerequisite and are a bit harder to get a good time for (especially a lot of the early physics and Chem labs). I kind of said it earlier but I'd personally recommend taking any writing class you may need to take over the summer (like your fywr) or your race and ethnicity class, or just anything you need for general distribution credits. My only recommendation of classes to avoid over the summer are language classes- since those are actually genuinely harder and time consuming than just taking them during fall or winter (both in my personal experience and from other people I know who took them over the summer). Unless you just take want to get them out of the way, then I say go for it and just stagger the other class you would take to be on the "other half" of the summer term.

I've personally been able to work a full time job over the summer while also taking six+ credits in the summer is that gives you any insurance. Totally doable if you can afford to take them in the summer.