Different demonstrative adjectives and pronouns are used depending on whether the object or person we’re speaking about is close to or far from the speaker.
If the object is close to the speaker, use “this” (singular) or “these” (plural)
If the object is further away, use “that” (singular) or “those” (plural)
This car is new.
These are my books.
That man is my uncle.
Those shoes are expensive.
There is no difference in the use of this/that/these/those when refering to people or things.
If this/that/these/those are followed by a noun, they have an adjective meaning. For example:
This book is boring.
If they are followed by the verb, they have a pronoun meaning:
This is my book.