SIPs are regular investments, which can be scheduled at a predefined day every month.
SIP amounts are withdrawn automatically out of your bank account.
This makes your savings more disciplined as your savings are withdrawn even before you plan your expenditure for the month.
SIPs boost your savings by reinvesting your gross investment.
SIPs also average out the cost of buying Mutual Fund units.
The earlier you start, the better it is as you can benefit from the power of compounding.