Short answers, pulled from the story.
The word bar derives from the metal or wooden barrier that runs along the length of the serving counter, separating patrons from the bartender's workspace. This physical object was called the bar; by synecdoche, the term extended first to the counter itself and then to the entire establishment.
During Prohibition in the United States, illegal bars were known as speakeasies, blind pigs, and blind tigers. These establishments operated in defiance of the ban on the sale and consumption of alcohol that was in effect during the first half of the 20th century.
Bar, pub, saloon, and tavern are different names for public drinking establishments that reflect different eras and regions. In the Thirteen Colonies of North America, a tavern served as a civic meeting place; saloons were central to working-class leisure in the 19th century; pub is the common British term. Today, regardless of the name on the door, the area where the bartender works is almost universally called the bar.
Laws vary by jurisdiction. In the United States, states such as California prohibit minors from entering a bar, though 8 states permit children to drink in a pub if accompanied by a parent. In the United Kingdom, minors are permitted to be present in a bar but generally may not drink there.
Types of bar include cocktail lounges, wine bars, beer bars, brew pubs, dive bars, music bars, sports bars, tiki bars, non-alcoholic bars, arcade bars, comedy bars, karaoke bars, drag bars, salsa bars, and strip clubs. Bars also form part of larger venues such as hotels, casinos, and nightclubs, and some people designate a room or area of their home as a home bar.
Notable fictional bars include the bar from the television series Cheers, the Copacabana bar from Goodfellas, the Double Deuce from Road House (1989), the Kit Kat Klub from Cabaret, the Korova Milk Bar from A Clockwork Orange, the Mos Eisley cantina-bar from Star Wars Episode IV: A New Hope (1977), and the Steinway Beer Garden from the video game Grand Theft Auto IV.