This is an entry in our Disneyland 101 Glossary: Disneyland Resort definitions in under 101 words, from Mouse Brief.
Disneyland Resort cast members make a great effort to seat parties together on attractions; as a result, some seats can go unoccupied and lower hourly ride capacity. At some popular attractions, Single Rider Lines exist to help fill these seats. If you choose to enter a Single Rider Line, it is likely that you will have a shorter wait than you would in a standby line, but you will not have your choice of seats or have the option to sit with your party. The names of attractions offering Single Rider Lines are available on the Disneyland website and app.
Other Services for Saving Time in Line at Disneyland Resort:
For information on virtual queues, visit our post here.
For information on the paid services for saving time in line, click here for our guide to Lightning Lanes.