"Post Soviet Russia" by Roy Medvedev contains a day-by-day breakdown of the events. The crisis was that the congress ruled to impeach Yeltsin after Yeltsin attempted to introduce rule by decree. Now Yeltsin attempted to dissolve the congress which was something he explicitly wasn't entitled to by the Russian constitution.

At that point the approval ratings of both Yeltsin and of the Russian parliament were below 25%. Millions of Russians were disappointed by the shock therapy liberalization and wouldn't take sides in the resultant stand-off.

Given whole army units (along with left and right wing radicals) came to the support of the congress while it was under siege the events can well be said to have been a real civil war.

As for the long run, it is not something not covered by this subreddit. The supporters of Yeltsin feared his fall would have resulted in a roll back to the soviet times or a in new right wing dictatorship (and these opinions were especially popular abroad.) Today it's his critics who note that his refusal to share or cede power resulted in a centralized and not extremely democratic system. The Russian politician Xenia Sobchak had noted the liberals in Poland had no qualms about ceding power to communists after unpopular reforms and it, if anything, made Poland more democratic.