Относительные местоимения в английском языке.

Вот подробное объяснение https://puzzle-english.com/directory/which-that-what?ysclid=ldajsvqypi868755083

"That" and "which" are both relative pronouns in English, which are used to introduce clauses that provide additional information about a noun or pronoun. However, there is a difference in how they are used.

"That" is generally used to introduce a clause that is essential to the meaning of the sentence and cannot be removed without changing the meaning of the sentence. For example, in the sentence "The book that I'm reading is interesting," the clause "that I'm reading" is essential to understanding which book is being referred to. "That" can also be used with both animate and inanimate objects.

On the other hand, "which" is used to introduce a non-essential clause, meaning that it provides additional information but is not necessary to understand the meaning of the sentence. For example, in the sentence "The book, which I found at the library, is interesting," the clause "which I found at the library" is not essential to understanding which book is being referred to. "Which" is generally only used with inanimate objects.

It's also worth noting that "that" is considered more formal than "which" and is more commonly used in written English, while "which" is more commonly used in spoken English.