There are 4 lanes (yes 4)
To start off, Top lane.
In Top lane, you're expecting a brusier champion. A champion that is innately tanky, and can take some harassment from enemy champions, and still dish out a moderate amount of damage. Since these champions can deal huge amounts of damage without extensive retaliation from the mid / bot lane champions, these are the champions that snowball the hardest. Snowball is a term meaning if you get one kill early, you can use that advantage and completely wreck house.
Examples of top lane champions are: Darius, Riven, Pantheon, Garen
Some wonky examples, but top lane champions are: Teemo, Rumble, Vladimir.
This is the lane for your highest burst damage champion. These champions will be usually AP, or AD assassins. You have the fastest source of income, as your creeps get there faster, and you are usually allowed to take the jungle's wraiths well into the match for a larger source of income. With all that, you should be leading the team in gold and level. The lane also has the highest number of ganking routes, so wards are mandatory or else you will be farmed by the enemy jungler.
Some examples of AP champions are: Kassadin, Annie, Lux, Katarina, Ahri
Some examples of Assassin champs are: Zed, Talon, Kha Zix,
This is the lane where you got the champion with the highest snowballing potential, at the same time a horrendous early game compared to most champions. This requires a babysitter, or known as the support. Bot lane consists of a ranged ADC and a support, but sometimes you might see two brusier champions at bot trying to get easy early kills off of the squishy ADC and support. Since there are 2 people in lane you gain less EXP compared to other lanes, but the support generally isn't supposed to take any CS (creep score) so your gold income shouldn't vary that much.
Ranged ADC examples: Varus, Ezreal, Vayne, Graves
Support examples: Sona, Lux, Soraka, Taric
Kill lane combos: Xin and Pantheon for example.
Lastly: The jungle.
I consider the jungle a lane. Do you have pathing? check. Are there creeps to kill? check. Does the other half of the "lane" have an enemy doing what you're doing? Check.
Anyways, The jungle consists of usualy a tanky jungler, who takes out the creeps in the jungler for their source of income and levels. The jungler will be constantly roaming around the map for their income, and with this comes the advantage of being able to help lanes in trouble. Imagine if the other enemy Mid champ is getting the advantage over your own mid-lane, you can rush in from the side brushes, kill the enemy mid as it will be a 2v1, and retreat, both of you gaining gold / xp, and now your mid lane champion has the advantage.
Important note, you must ALWAYS use smite while in the jungle. If not, you will have 0 control over the buffs, the dragon (which gives global gold), or baron (which gives global gold and a massive buff to your entire team)
Jungler examples are: Udyr, Shyvana, Lee Sin, Fiddlesticks, warwick, etc