Capital budgeting is the process of evaluating long-term investment projects and determining whether they are worth funding through debt, equity, or retained earnings. It involves estimating future cash flows of potential projects, evaluating them using techniques like net present value, and choosing projects that increase shareholder value and have returns higher than the company's cost of capital. The objectives of capital budgeting include setting investment priorities, purchasing assets that generate positive returns, aligning investments with marketing plans, keeping pace with projected growth, and maintaining an optimal debt level.