Elo Hell is when you've lost a lot of placement during initial placements stages. The difference is that, once you're in a placement, you can only gain like 17 or 18 elo for a win (and losses are a similar number like -13 & -14) or maybe that depends on whether the team was Blue or Purple. I have a second account where I was unfortunate enough to be in bad placements both during and after the initial thing that calculates your placement-elo but this main account just received another +74 elo from its most-recent ranked win (I don't do ranked that often yet but I have a 6/1 win/loss record with it thus far).
Anyway, imagine if you had a top elo-rate of 1400 or so during your initial placement, but then it fell down to 1200- due to several bad match-making streaks, then another 200 to take you down to 1000, basically, you will be stuck at what-ever elo your elo-placement is in for quite a while simply because of the sheer amount of wins (without losing) that you need in order to climb from 1000 to 1400 (now let's take 400 total elo to be gained and divide that by 18 [this is being generous]).
How many winning games are needed to gain 400 elo now ? 400 ÷ 18 = a whopping 29 matches. How long does it take to play a match ? Let's say that you really have to fight for all of them in order to win. Let us say it's one hour per match... what that means is that you're looking at around 30 hours of play-time at the minimum. How many hours are in a day ?
Unless you can afford to no-life all day, each and every single day, that is a significant chunk of time out of the week, and I would say a minimum of at least two weeks before you can go from 1000 to 1400, and even then, that is assuming that you're lucky enough (yes, your own individual skill-level does play a role in your over-all elo, however, compare a change of 13 elo per game to a change of 74 elo per game, then you get an idea of that "elo hell" phase of "VERY EXPERIENCED" players being "stuck" there at that elo, all being pitted against one another, but let's be honest about another part, too, and that's one's attitude towards game-play, considering that those "toxic" people who rage/fuss against their own team actually make their own team do worse & play worse over-all, thus in turn, placing those types of people in that low elo, because their lack of confidence-boosting/morale-raising leadership-skills simply causes a lot of in-fighting, thus in turn placing them in their low elos [amongst anybody else who was unfortunate enough to be matched on the same team as them], because those types of people actually deserve to be at such a low elo).
I still have like 3 or 4 more ranked matches to go until my Elo-Heaven phase expires. D=
Once you've done your 10 you suddenly got kicked into elo-hell. I think...