1. Inside means within something else.

Pattern: verb + noun + inside + noun
There are some little toy animals inside the box.
She put the money inside the envelope.

2. Inside (adverb) means indoors, within a building.
It started to rain, so we went inside.

Fact
The Brownie box camera, introduced by Eastman Kodak, sold for $1.00 in 1900. The camera's 6-exposure film sold for 15 cents.      .. More >>