The term business credit normally refers to one or more credit cards which can be used to make purchases on behalf of a business. A business credit card will usually have both the business name and the card holder's name printed or embossed on the card. In most cases the cardholder will have provided a personal guarantee when applying for the card. A personal guarantee ultimately makes the card holder liable for all charges made on the card.
The term corporate credit can be used to represent a number of different business funding options including credit cards, trade credit, bank loans, equipment loans, merchant cash advances, etc. Business owners should be able to utilize corporate credit and make get the funding the need for their business without a personal guarantee. Corporations (and this includes all types of corporation including LLCs) are legally separate entities. This means that forming a corporation is like giving birth to a new person who is over the age of 18 and therefore independent of the person who created it. As a business owner it makes sense to form a corporation and then do everything you can to distance yourself from that corporation. This includes making sure that you never commingled assets, sign personal guarantees, etc.