Acronyms and abbreviations are both ways of shortening words. An acronym is when we just use the first letters from each word in a name or phrase. An abbreviation is when I still have some vowels or consonants from the same word in that word.
Acronyms和abbreviations都是词的缩略方式。不同的是：acronym取的是首字母，abbreviation会在一个词里面取一个音节，或者几个元音，辅音字母。

boulevard = blvd.
(尤用于地址、地图或标志中）路，道
library = lib.
图书馆
NB = (Latin) nota bene的缩写
意思是：note well 特别注意
NASA = National Aeronautics and Space Administration
美国国家航空航天局, 美国宇航局
FBI = Federal Bureau of Investigation
联邦调查局
POTUS = President of the United States
美国总统
BASE jumping = buildings, antennas, spans, earth formations jumping
极限跳伞，定点跳伞


gtfo = get the fuck out 出去
lol = laugh out loud 大笑
irl = in real life 在现实生活中
rofl = rolling on the floor laughing 笑倒地
g2g = got to go 得走了
afk = away from keyboard 离开键盘
ttyl = talk to you later 待会儿聊
JK = Just Kidding 开玩笑

NFW = No Fxxxing Way 不可能啊！！！
BFF = Best Friend Forever 最好的朋友！
IG or Insta = Instagram
TYT = Take Your time 慢慢来别着急！
SMH = Shaking My Head (失望，不同意) 摇头！
YGTR = You Got That Right 对啦！