The Apple MacBook Air Early 2015 has an 802.11n WiFi standard which is better than most portable PCs of a comparable age and type to it. Most portable PCs of this type and age have an 802.11a WiFi standard. This Apple laptop also have 802.11ac and 802.11b and 802.11g WiFi standards.
This laptop's Wi-Fi standard (802.11n) is actually the best Wi-Fi standard amongst all comparable spec laptops that are a similar age to the MacBook Air Early 2015.
An 802.11a WiFi standard is the worst Wi-Fi standard across comparable types of laptop.