There is a long-standing popular view of grammatical analysis which uses the structure of one language (originally Latin, or contemporarily English the analysis of which was influenced by Latin), then analyzes other languages according to the categories of the standard language. Over a century ago, a competing model developed which sought to describe languages "in their own terms", especially in the works of Franz Boas and his students.
Contemporary linguistics generally accepts that there need not be definite articles or jussive moods in all languages, however we do frequently use those terms to refer to semantic properties. Bantu languages, for example, do not usually have "definite articles", but they often have complex ways of signalling definiteness, whatever that means (turns out that "definite" is a complex package deal even at the level of semantics). We frequently find, in investigating a new language, that the language may not make a grammaticalized distinction between "past", "present" and "future" tense, but all languages have tools that allow them to communicate information about the past, present and future. English has a past, but Logoori has 7 pasts, meaning distinct inflectional forms. Rather than getting swamped in a procrustean terminological quagmire, we tend to focus on describing the semantic and syntactic properties of each construction.
There have been so many results coming from the enterprise of language description following this view that it would be meaningless to claim that there is a "major result", other than to say that "languages are not defined in terms of the traditional analysis of English (Latin)".