Compound annual growth rate is the constant yearly rate that connects a starting value to an ending value. CAGR = (ending / starting)^(1 / years) − 1. It smooths a bumpy path into one annual rate. It does not show the path between the two dates.
A value that goes from $10,000 to $20,000 in 10 years has a CAGR of 7.18% a year. Doubling in 10 years is not 10% a year, because the gains themselves earn returns.
Deposits and withdrawals in the middle years are not modeled. If money was added along the way, this rate overstates how hard the investment worked.