The adjective is 'neu' and means 'new'. The difference here is only in the endings : 'neuE' ending in E . 'neuES ending in ES. There are other endings like 'ER' , 'EM' , 'EN',etc ,, you will come across them. They are attached to adjectives in general and determined according to: - The article of the following noun ( the noun following the adjective) - The position of the following noun in the sentence( whether nominative,accusative or dative ) You have to use some grammar book to learn more about those concepts. I will give you a general idea here and some examples: Die NEUE Sprache. Here you attached an 'E' to the adjective 'neu' because: - The following described noun 'Sprache' has the article 'DIE' - The position of the noun 'Sprache' is nominative in the sentence. Ein NEUES Auto Here 'ES' at the end of 'neu' because: - The article of the following noun 'Auto' is 'DAS' - The adjective 'neu' is preceded by the undefined article (unbestimmter Artikel) 'Ein'. Those are many regulations ,that you have to understand and learn to be able to determine the correct ending of the adjective in any sentence. Hope this gives you some idea about the subject !

They are different inflexions of the same word. They both mean "new".