Formatting is what makes a spreadsheet actually readable — number formats, borders, and color.
The same underlying value 1000 can display as 1000, 1,000.00, ₹1,000, or 100000% depending on the format applied — the number itself never changes, only how it's shown.
Found in the Home tab. A bolded, colored header row is the single easiest change that makes almost any spreadsheet easier to read at a glance.
Home tab → Conditional Formatting changes a cell's appearance automatically based on its value — for example, coloring every cell below 40 red without checking each one by hand. The formatting updates live as the underlying numbers change.