## TL;DR
Corporate finance addresses how firms raise capital and make investment decisions. Capital structure (debt vs equity) and valuation (what assets are worth) are the core concerns.

## Core Explanation
Investment decisions: NPV (accept if >0), IRR, payback period. Financing decisions: debt (bonds, loans — fixed obligations, tax deductible interest) vs equity (stocks — residual claims, dividends discretionary). WACC (Weighted Average Cost of Capital) is the discount rate.

## Detailed Analysis
The CAPM (Capital Asset Pricing Model): E(R) = Rf + β(E(Rm)-Rf). Beta measures systematic risk. Portfolio theory (Markowitz, 1952) demonstrates diversification reduces risk without sacrificing expected return.

## Further Reading
- Aswath Damodaran: Valuation Resources
- Investopedia
- CFA Institute