Cardinal numbers are the basic numbers we use to count things. They tell us "how many" of something there are. For example, if you have three apples, the word "three" is a cardinal number. Other examples include one, two, four, and ten. These numbers help us quantify objects in our daily lives. In addition to counting, cardinal numbers are also used in various situations, like telling the number of people in a room or the number of books on a shelf. They are different from ordinal numbers, which indicate position or order, such as first or second.