The loan agreement lists the terms under which a loan is given. The bank is the lender, and any borrowing entity--individual, partnership, company--is the borrower. The loan agreement covers many of the same terms and conditions as a promissory note, although it is longer and more complicated.
The subsidiaries remain private. They are private subsidiaries of a public company. Think about it: if a subsidiary went public, that would mean that its shares were being offered to the public, instead of all being owned by the parent company, and so it would no longer be a subsidiary.
These 10 facts about space will blow your mind. A parent company is one that owns or controls another company, known as the subsidiary. The parent company is able to direct the business practices of the subsidiary because it controls the voting, thus making determinations like who should sit on the board of the subsidiary.