Compound interest pays interest on interest, so the growth curve bends upward rather than running in a straight line. Set a starting balance, an optional monthly contribution, a rate and a term to see the final balance split into what you put in and what the interest added.
For a lump sum, A = P(1 + r/n)^(nt), where P is the principal, r the annual rate, n the number of compounding periods per year and t the number of years. Regular contributions add a future-value-of-an-annuity term on top.
Less than most people expect. At 6% for 10 years, annual compounding turns 10,000 into 17,908 and daily compounding into 18,220 - a difference of under 2%. The rate and the time horizon matter far more than the frequency.
No, the result is a nominal figure. To think in today's money, subtract expected inflation from the rate: 7% growth with 3% inflation is roughly 4% in real terms.