Book Value represents the value of an asset as recorded on the company's balance sheet. It is calculated by taking the original purchase price of the asset and subtracting out any accumulated depreciation, amortization, or impairments that have been recognized for that asset over time.

For example, if a company purchases machinery for $50,000 and accounts for $10,000 in accumulated depreciation over several years, the book value of that machinery would now be $40,000. It reflects the accounting valuation of the asset rather than the current market value.

In the context of company valuation, the term 'Book Value' can also refer to the value of the company's total assets minus its liabilities, essentially representing the net asset value as presented in the balance sheet. It's useful for investors and analysts as a measure to understand a company's financial health and in making comparisons among companies in the same industry.