Buy-Side vs Sell Side.
The Buy Side refers to firms that purchase securities and includes investment managers, pension funds, and hedge funds. The Sell-Side refers to firms that issue, sell, or trade securities, and includes investment banks, advisory firms, and corporations. Sell-Side firms have far more opportunities for aspiring analysts than Buy-Side firms usually have, largely due to the sales nature of their business.
The article below further expands on their differences and might be able to help you figure out which side of asset management you might be most inclined to.