This is the 974th most frequent Bulgarian word.
социални
"Социални" means "social" in English.
In this sentence, "социални" (social) is used as an adjective to describe "мрежи" (networks), indicating their nature related to social interaction.
Социални мрежи като Facebook и Instagram са много популярни.
Social networks like Facebook and Instagram are very popular.
Here, "социални" (social) modifies "науки" (sciences), relating them to the study of society and human behavior.
Обученията в социални науки са важни за разбирането на обществото.
Studies in social sciences are important for understanding society.
In this instance, "социални" (social) describes "умения" (skills), associating them with interpersonal relationships and communication.