3 flight legs over several months for the number of miles you would need for only 2. (brooklyntropicali.com)
This term is however rather used for a flights with three and more flight legs making an round booking. (flynous.com)
In addition to often yielding lower fares, pricing flight legs separately allows you to mix and match carriers to find the best combination of both price and schedule for your needs. (thepointsguy.com)