'This' and 'these' - ce, cette and ces in French - are called demonstrative adjectives. They are used when you want to point out a specific thing or person or to emphasise something.
They come before a noun and agree with the noun. For example:
Ces means 'these'. It's used before a noun in the plural form. For example:
|Masculine||Masculine (before vowel or -h)||Feminine||English|