What does BB mean in baseball?

Could you please clarify for me, what exactly does the abbreviation "BB" signify in the context of baseball? Is it a term used to describe a specific play, a statistic, or perhaps a rule? I'm curious to know the exact meaning and its relevance to the sport. Additionally, if there are any other common abbreviations or slang terms used in baseball that might be similar to "BB", could you also provide some insight on those? Thank you in advance for your help in deciphering this baseball jargon.