They have the same size casing, but the bullet is longer and heavier in Long Rifle.

Bullet weight.

The latter is longer and more powerful. I have not seen any .22 Longs for some time, but this shell is listed in my gun books.

A long time ago, there was only the original 22, the first metalic cartridge to really catch on. Nowadays we call that one the 22 short. People then improved it, lengthened the case to fit more gunpowder in. This was the 22 long. Then people improved it some more, they lengthened it just a tiny bit more, but put a much heavier bullet on it (the bullet was the same diameter, just longer) this was the 22 long rifle

Any gun that can shoot 22 long rifle can also shoot 22 long.

Originally the 22 short used a 29 grain bullet and 4 grains of "blackpowder" type gunpowder. The original 22 long used the same 29 bullet but 5 grains of blackpowder and the 22 long rifle used a 40 grain bullet and 5 grains of blackpowder
There was also a 22 Extra Long, which had a 40 grain bullet on 6 grains of blackpowder

So the 22 long was actually faster than the 22 long rifle

But then 'smokeless powder' was invented, and it was great stuff, almost twice as potent, and then 22 long rifles were loaded hot enough so they were faster than 22 longs. Plus, nowadays, there is a type of 22LR called 'hyper velocity' that can really zing! these can fire in any regular 22LR gun as well. They generally take a page from the original 22 long and just use a lighter bullet. Because the lighter bullet is also shorter, sometimes they strectch out the brass case and put in extra smokeless powder, but the overall length is the same, so it works just fine.