"Fusion" What is it?

According to the Oxford University Press (2018) fusion is defined as ' The process or result of joining two or more things together to form a single entity.  '

In my opinion Fusion is the equal merging of more than one item in equal parts, to create one single product. Within dance it is often seen when watching choreography the simple use of one or two movements within a certain style of dance for example, including a simple acrobatic walkover within a lyrical or jazz routine. I would not necessarily regard this as a fusion of dance styles more of a slight mesh. But then I am unsure what i would regard this as and whether the term 'slight mesh' really covers this specific example. 

So this has made me question where is the balance, when is it that one style becomes another or there is a true fusion in equal parts. 

Ibrakovic (2016) explores how crucial fusing dance styles are to exploring the boundaries of dance styles.  

'How are we supposed to think outside of the box, if we’re not even quite sure what the box looks like? It’s extremely important to understand the structure of one dance style and ideally to master that style, so that you can then fuse it with other styles.' 

But this then leads me to further question who decides what the parameters of a dance style are, is one persons normality another's extreme.  Also what are the structural components of dance styles are these just ideals or are they specific movements that are involved within a dance style? 

Bibliography
Oxford University Press (2018) Fusion Definition [ONLINE] Available at <https://en.oxforddictionaries.com/definition/fusion>

Ibrakovic (2016) What is dance fusion and how can it enhance our dancing? [ONLINE] Available at <http://www.socialdancingblog.com/en/was-ist-dance-fusion-und-wie-kann-es-unser-tanzen-bereichern/>