Question

How are percents used and what do they mean

Answer 1

They're used to measure or divide things¿

Answer 2

Percents are just parts of an whole. Percentages are an important part of our everyday lives. Percentage is a very handy way of writing fractions. Percentages can be compared more easily than fractions.Some example are:Shops advertise discounts on products.  These discounts are percentages.
"Up to 50% off marked prices"Financial institutions quote interest charged to the client on loans, or interest paid for money invested, as a percentage.

"Housing Loans-4.95% p.a. for the first 12 months"

Interest paid may be as Simple Interest or Compound Interest.Companies describe their success or failure as an increase or decrease in profit levels.

"C-Company profit down by 15% for the last financial year"A salesperson may be given a commission as payment for selling goods.  The commission can be a percentage of the sales made.
"Position Vacant:  20% commission on all sales to the successful applicant." Articles such as antiques or jewellery may increase in value as time goes by-appreciation. Items such as equipment and machinery usually decrease in value-depreciation