Capital budgeting involves planning long-term capital expenditures and investments. There are various techniques used to evaluate capital budgeting proposals, including non-discounting methods like payback period and accounting rate of return, as well as discounted cash flow methods like net present value, internal rate of return, and profitability index. Each method has benefits but also limitations, such as not accounting for the time value of money. Cost of capital refers to the minimum return required to undertake an investment and involves calculating the specific costs of different sources of financing like debt, equity, and retained earnings, as well as weighing them to determine an overall cost.