In the English language,many words seemingly have the same; these words are known as ‘synonyms’. However, having a real appreciation of the language and usage of words means you do not treat synonyms as simply interchangeable. Yes the words do have the same meaning essentially but their connotations can be quite different. Advanced writers understand the subtle differences in the connotations of synonyms and use those differences to their advantage to make their writing more precise and interesting and also to influence the way the reader feels about the author’s research.
When writing, I highly recommend you use a synonym dictionary (a thesaurus) as a first place to get ideas for different words. However, I don’t recommend you use a synonym dictionary as the bible to find substitute words just for the sake of variety. Using synonyms for variety does help make writing more interesting, but this rule generally applies to prose, literature and journalistic writing. It applies much less to technical and academic writing. In academic writing, you need to use the exact same term or phrase (or an abbreviated form of it) in many instances if referring to the same concept or object. And further, you need to choose the correct or most suitable term that will convey the connotation that suitsthe situation in other instances.