What is the difference between active scan and passive scan?

Question

What is the difference between mWifiManager.startScanActive() and mWifiManager.startScan().
What is the difference between active scan

Answer 1

please note that an active scan will consume more energy and as "ordinary" wifi access points broadcast their beacons several times per second, an active scan is rarely needed. e.g. requesting a list of wifi networks in reach takes approx 0.7 seconds to finish. so this should be sufficient...