First, botanists do not consider strawberries to be true berries. True berries, like cranberries and blueberries, have seeds inside them. If you however cut open a strawberry, you will notice that there are no seeds inside.
Technically, strawberry is the enlarged end of the plant’s part called the “stamen.” Usually, a fruit develops from the flower’s ovaries. However, most scientists and even cooks still consider strawberries to be fruits.
The “seeds” you see on the outside of a strawberry are the plant’s ovaries and are called “achenes.” Each seed is technically a separate fruit that has a seed inside of it.