Inflation happens when the overall price of goods and services rises over time — usually when demand outpaces supply, or when the cost of producing things (wages, energy, materials) goes up. A little is normal; a lot erodes what your money can buy.

Solar panels are made of cells that convert sunlight directly into electricity. When light hits the cell, it knocks electrons loose and creates a flow of current, which an inverter turns into the kind of power your home can use.

Compound interest is interest earned on both your original money and the interest it has already earned. Over time that “interest on interest” snowballs, which is why starting early matters so much.

A heat pump moves heat rather than burning fuel to create it — pulling warmth from the outside air or ground to heat your home, and running in reverse to cool it. Because it transfers heat, it can be very efficient.

A mutual fund pools money from many people to buy a basket of investments — stocks, bonds, or both — managed as one. It’s a simple way to spread risk across many holdings instead of betting on one.