What is the difference between direct investment and investment from a broker in mutual funds?

Simple, with a direct plan mutual fund you pay zero commissions. With regular plan mutual funds, you pay commissions as indirect fees.

These commissions add upto 40% in the long run because most equity mutual funds incur about 1.5% annual commissions. Imagine giving away 40% of your portfolio. This is real money. And yours.

The NAVs of the two are different,but everything else remains the same. So one is like wholesale and the other is a retail price.