The first key thing to understand is the difference between inside and outside basis. So if we think about a company purchasing assets, property plant and equipment for a hundred, and let's assume that they're financed by equity. This is inside the balance sheet of the company. So, this is what we call the inside basis. It's sometimes known as the asset basis as well. So, this is the original cost of the asset less any depreciation. And remember that tax depreciation is different from shareholder's depreciation. Conversely, the shareholding in the company, this is the price that the shareholders paid for the shares, which is not necessarily the same as book equity either because the company has generated retained earnings, or where the shareholders purchase the shares after the company was formed for a much higher price than the book value. And this is known as the outside basis or the stock basis, which is the purchase price of the shares. So to reiterate confusingly, the asset basis for the shareholders accounts versus the tax accounts can be different. And most of that is caused by different depreciation and amortization between shareholders accounts, or gap accounts and tax accounts.