Mutual funds pool together money from investors to invest in a portfolio of securities like stocks and bonds. In India, mutual funds are regulated by SEBI and operate under an asset management company. They can have different objectives like income, growth, or balancing returns and risk. Funds are classified by whether investments are open-ended and continuous or closed with a fixed duration, and by the type of securities held like money market instruments or equities. The structure of the Indian mutual fund industry involves asset management companies, AMFI as the industry body, and SEBI regulations.