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muscle growth only comes from resting and the regeneration proces.
with that in mind, picture yourself working on your biceps on a day. during this workout your biceps will get small micro-like ruptures in them, because they expand. if you dont give your biceps the time to heal those ruptures, you'll only make the ruptures worse.
however, eating the right amount of protein should speed up the regeneration proces.
as for your question, if you want to lift two days in a row, thats fine, but yes, work on a different muscle group. also try to do a muscle group thats the furthest away from the group thats currently regenerating. example: if you did your chest today, dont work on your back tomorrow, do your legs.
my 2 cents, hope theyre useful to you.