If you're from a country that doesn't have emotional support animals, here's how it works.

Sometimes places ban or restrict animals. For example, an apartment building might not allow dogs. Or an airline might charge you money to transport your cat. But the law requires them to allow service animals, for example guide dogs for the blind. A newer law also requires some of these places to allow emotional support animals, ie animals that help people with mental health problems like depression or anxiety. So for example, if you're depressed, but having your dog nearby makes you feel better, then a landlord has to let you keep your dog in the apartment. Or if you're anxious, but petting your cat calms you down, then an airline has to take your cat free of charge.

Clinically and scientifically, this is great. Many studies show that pets help people with mental health problems. Depressed people really do benefit from a dog who loves them. Anxious people really do feel calmer when they hold a cute kitten.

Legally, it's a racket.

https://www.astralcodexten.com/p/the-emotional-support-animal-racket