Jason bought a new camera for his brother.

In the given sentence, Jason, camera and brother are the nouns.

The noun "Jason" describes a person, "camera" describes a thing and "brother" describes a person.

She kept the food on the table.

In the given sentence, food and table are the nouns.

The nouns "food" describes a thing and "table" describes a thing.

He works as an engineer in London.

In the given sentence, engineer and London are the nouns.

The noun "engineer" describes a person and "London" describes a place.