What are the foundations of Islamic creed (Aqidah) and what are its branches?

The fundamentals of faith are belief in Allah, His angels, His books, His messengers, the Last Day, and divine preordainment, both good and bad. The branches are what stem from these fundamentals. A general belief in the fundamentals is a condition for a Muslim's faith. The faith of one who is unaware of some of the branches is valid, but it is not permissible to deny them after their establishment by religious texts; rather, one must believe in them.