A mat is usually flat and rectangular. It provides protection for the people or things that are on it or under it.
A welcome mat is placed outside of a person’s home. People wipe their feet on the mat before they enter.
A floor mat rests underneath the feet of a person who drives a car. The mat protects the carpet in the car.
When you step out of a bathtub or a shower, a bath mat provides a place for you to stand. It also helps prevent you from slipping on a wet floor.
A place mat goes on a table. It’s a place for your napkin, silverware, and your food.
A wrestling mat provides protection for wrestlers. It’s soft and helps prevent injuries.
A yoga mat is used by people who do yoga.
Note: The sharp "t" sound in "mat" disappears when this word is used with other words in a sentence. In isolation, you’ll easily hear the "t" as the end of this word; among other words, it’s not easy to hear the "t," but the "t" sound is there.