Taxable and Financial Income

Why are there differences between taxable and financial income? What are some examples of permanent and temporary differences? Why do these differences exist? How do they affect the financial statements?
Net Operating Losses

How are the tax benefits of net operating losses (NOL) disclosed on financial statements? Which is more beneficial to an organization, an NOL carry forward or an NOL carry back? Explain why. When would a company decide to forego a carry back?

Deferred Tax Assets and Liabilities

How are deferred tax assets and deferred tax liabilities derived? How do they relate to the difference between tax expense and taxes payable? How could an organization have a tax receivable? Why is the tax expense reported on the income statement comprised of current and deferred tax?