This is the 12th most frequent French word.
ce
"Ce" is a demonstrative pronoun or adjective in French meaning "this" or "that."
'Ce' is used as a neutral pronoun in 'ce que' to introduce a relative clause meaning 'what'.
Ce qu'il a dit est vrai.
What he said is true.
Demonstrative pronoun 'ce' is used to indicate 'this' referring to the noun 'livre'.
Ce livre est intéressant.
This book is interesting.
'Ce' is used as a neutral pronoun to refer to the following clause immediately after 'est' (construction for presenting or identifying).