A Mutual Fund is a type of collective investment that pools a large amount of money from the investors, institutions and individual which was then invested in accordance to a prospectus agreed (type of funds). The Mutual Fund is usually managed by a fund manager, which assigned by the issuer financial institutions or companies.
The fund Manager will manage and invest the fund portfolio accordingly, to met the investment objectives and strategy. The advantage to invest in Mutual Fund as below
– Capital appreciation over period of time
– Professional management to met the investment objective
– Liquidity where you can buy / sell funds
– Lower risk (usually the fund will be diversified)  
The concepts more or less are very similar to bank, where people deposit money in banks and in return the depositors will receive the interest. The money will then manage by the financial professional to bring more returns, example borrow money (housing loan) to consumers in exchange for higher interest returns.   
Other than the Fund Manager, the below divisions also playing a very crucial roles which including
– Trustee who holds the asset of the fund on behalf of the fund holders
– The management who promotes and administrative the fund operations
All the mutual fund prospectus is usually scrutinized by the authorities such as Central Bank before the funds are available to public for subscription. Hence, to invest in Mutual fund is even safer other than the advantages listed above.
Investors are advised to do their own research before signing up the funds. Things to determine in advance, such as cost and charges (remember the fund is managed by professional, therefore management changes will be always in picture).