'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:
ce before a masculine singular noun, eg ce matin - this morning
cette before a feminine singular noun, eg cette semaine - this week
Ces means 'these'. It's used before a noun in the plural form. For example:
ces voitures - these cars (voitures = feminine plural)
ces amis - these friends (amis = masculine plural/mixed group)
ces hommes - these men (hommes = silent -h and plural)
ces oranges - these oranges (oranges = vowel and plural)
