We will examine how different types of dictionaries treat the same word.

A monolingual dictionary gives explanations in simple English:

An entry from Longman Dictionary of Contemporary English explaining the word management
Longman Dictionary of Contemporary English

You can read more about dictionaries here.

A dictionary of synonyms suggests alternative words:

An entry from Collins English Thesaurus explaining the word management
Collins English Thesaurus

More about dictionaries of synonyms can be found here.

A dictionary of collocations shows how a word can be combined with other words and parts of speech:

An entry from Oxford Collocations Dictionary explaining the word management
Oxford Collocations Dictionary

Read more about dictionaries of collocations here.

Finally, a thesaurus is built on concepts and ideas and will give you lots and lots of closely and more remotely related words and expressions:

A page from Rogets Thesaurus showing the entry for management
Roget’s Thesaurus

A thesaurus gives you ample opportunity to vary your text, but you need to understand nuances in meaning. Under Vb. (Verb) we find neutral phrases such as be in charge and have overall responsibility but also expressions from working life such as take the helm (of a ship), take the chair (lead a meeting) and hold the reins (of a horse). We also find more informal phrases such as wear the trousers, which implies someone who is in control and makes decisions. You would not use that expression in a serious text about the CEO of a company!

Read more about thesauri here.