What is quant investing?

Quant investing means investing by numbers and rules instead of gut feeling. For example: "buy the 30 lowest-PER stocks and rebalance once a year" — set the rule first, then follow it.

You don't need fancy software. A simple filter like "dividend yield above 3% and profitable for 10 straight years" is a perfectly good quant rule. What matters is sticking to the rule you set.