Being inside something
Encoding Strategies:
linguistic

de
from
+
enter
to go inside
Dentro means inside and is literally something that's "from0 inside1."
dentro
inside, indoors
Indicates that something or someone is in the interior of a physical space, container, or abstract boundary
Vamos dentro, hace fríoLet's go indoors, it's cold.
El gato está dentroThe cat is inside
dentro de [something]
inside of, within
When identifying the actual space or container, the 'de' shows that something is coming from or is inside of something else.
Las llaves están dentro del cajónThe keys are inside of the drawer
Hay un regalo dentro de la cajaThere is a gift within the box