Branding is glue.

"Glue (noun) - 
something that binds together" Merriam-Webster Dictionary.

I define a brand as "the meaning people attach to you and your offer". Branding is "the management of meaning". A Brand Strategy is a plan to manage meaning. It defines an audience that we serve and the meaning we want that audience to attach to us. Therefore:

Branding strategy. =
 A plan 
that binds.

It's glue. A mindset. A business essential.