Why do strawberries have seeds outside?

First, the fruit is formed from flowers. Flowers include: ovary, ovule, petals, sepals, stamens . Most of them are attached to a section called flower soles.

Strawberry.

Normally, the ovule after fertilization will become a thicker growth seed and gourd, forming fruit. The remaining parts of the flower will fall.

However, strawberry flowers have a lot of ovary. When fertilization takes place, these ovaries form a lot of small fruits (indeed) but they do not swell up, but instead, the empire will grow thicker to form the edible red pulp flesh. (fake fruit).

It will indeed cling to the surface of the fake fruit. Parts of the flower type will fall. So the small particles that we see outside of strawberries are actually their fruits. Inside each fruit contains a seed