Baseball: Baseball is a bat-and-ball game played between two opposing teams who take turns batting and fielding. The game proceeds when a player on the fielding team, called the pitcher, throws a ball which a player on the batting team tries to hit with a bat. The objectives of the offensive team (batting team) are to hit the ball into the field of play, and to run the bases—having its runners advance counter-clockwise around four bases to score what are called "runs". The objective of the defensive team (fielding team) is to prevent batters from becoming runners, and to prevent runners' advance around the bases. A run is scored when a runner legally advances around the bases in order and touches home plate (the place where the player started as a batter). The team that scores the most runs by the end of the game is the winner.
Source: https://en.m.wikipedia.org/wiki/Glossary_of_baseball
Minor League Baseball: A hierarchy of professional baseball leagues in the Americas that compete at levels below Major League Baseball (MLB) and provide opportunities for player development and a way to prepare for the major leagues. All of the minor leagues are operated as independent businesses. Most are members of the umbrella organization known as Minor League Baseball (MiLB), which operates under the Commissioner of Baseball within the scope of organized baseball.
Rookie, Rookie Advanced, Class-A, Double-A, Triple-A
Some players advance quickly and are called up to the major league teams. Others spend years trying to make it and eventually wash out.
Manager: In baseball, the field manager (commonly referred to as the manager) is the equivalent of a head coach who is responsible for overseeing and making final decisions on all aspects of on-field team strategy, lineup selection, training and instruction.