What are 'Data Types' and why do they matter?

Think about a market stall. You have some items sold by weight (rice), some by count (eggs), and some by length (fabric). You wouldn't try to weigh a yard of lace, would you?

Data types are the same. A computer needs to know if it's dealing with a number (like 500 Naira) or text (like 'Ikeja'). This helps it know how to handle the data.

If you try to add a word to a number, the computer gets confused. Understanding data types is like knowing the difference between pepper and salt before you start cooking.