The following excerpt is taken from a publication of the American Institute of Certified Public Accountants (we won't give the title since it is the answer to one of the questions):
Great strides have been made by the FASB and the IASB to converge the content of IFRS and U.S. GAAP. The goal is that by the time the SEC allows or mandates the use of IFRS for U.S. publicly-traded companies, most or all of the key differences will have been resolved. Because of these ongoing convergence projects, the extent of the specific differences between IFRS and U.S. GAAP is shrinking. Yet significant differences do remain. For example IFRS does not permit Last In First Out (LIFO) as an inventory costing method.
a. What is the FASB?
b. What is the IFRS?
c. What is meant by GAAP?