lol is a greeting in the English language. It is common between two people in a non-formal (informal) setting, but can also be used in a formal setting. There are also many other ways of saying "hello", for example a wave of the hand, a salute or a bow (both very formal), a handshake (a little formal) or a high five (very informal). Saying "hello" is a sign of politeness, especially when it is said in a friendly way. "Hello" was first used in writing in about 1833.
Hello is also used by many people when they are answering a phone call. Sometimes, people can say "Good morning" in the morning or noon, "Good afternoon" in the afternoon,"Good evening" in the evening, and Good night in the night-time/when it's dark.
Some more versions of the word "hello" include; Hi, Hallo, Hiya, Howdy, Hey, Howya, 'Sup, Yo, 'Yello, Herro, Yeller (mainly in the southwestern United States) and many more.
On instant messaging, people greet others using "hello" or other versions of it.
The opposite of hello is goodbye, which is said when people leave.
The German word for "hello" is "Hallo", and the French word is "bonjour", the Spanish word is "Hola".