SNA is the airport code for John Wayne Airport, also known as Orange County Airport, also known as Santa Ana.
It's the closest airport to
Disneyland and Newport Beach. It's also has the nicest airport terminal in Southern California and convenient rental car service right in the parking structure (no rental car shuttle for the major rental car brands).
The next closest airport, Long Beach (LBG), is burdened with a historic terminal that's completely inadequate. The region's major airport, Los Angeles International (LAX), is a huge, crowded, busy airport with rental car pickup several miles away.
For anyone traveling to the Disneyland Resort, John Wayne Airport should be the first choice.