Syndicated Loans Terminology - Borrower & Sponsor I am trying to understand what is the difference between the Borrower and the Sponsor entities in a syndicate loan agreement.

Namely, it looks like quite often, the Borrower entity will be a Company that is getting acquired by the Sponsor entity - what I don't understand is if the Sponsor is acquiring the Company, why isn't the Sponsor borrowing the money?
It sounds like you're talking about a leveraged buyout. In these transactions, a private equity firm (or sponsor as you call them) will acquire an operating company. The debt for the acquisition - raised via the capital markets - will reside on the target company's balance sheet. This debt will be used to pay the previous owners (another PE firm, founders, etc.. whoever owned the company previously). The PE firms will never take debt onto their own balance sheet, and during the course of ownership often raise additional debt on the company to pay themselves dividends.