This is the 139th most frequent Ukrainian word.
цих
"Цих" means "these" in English.
In this sentence, 'цих' is the genitive plural form of 'цей' (this) and describes which people the speaker is referring to.
Я бачив цих людей учора.
I saw these people yesterday.
Here, 'цих' again serves as the genitive plural form and is used as the object of the preposition 'про' (about) to specify the individuals discussed.
Ми розмовляли про цих друзів.
We talked about these friends.
In this context, 'цих' is combined with 'дітям' in the dative case to indicate whom the action of helping is directed towards.