This is an entry in our Disneyland 101 Glossary: Disneyland Resort definitions in under 101 words, from Mouse Brief.
Across the Disneyland Resort, you will see signs indicating where strollers should or should not be parked. Strollers are not allowed in most attraction queues or attractions, and “Stroller Parking” signs indicate designated areas where guests should leave strollers while not in use. With frequently heavy crowds, cast members prioritize keeping walkways clear, so you may return to find that your stroller has been moved (especially if you did not leave it in a designated parking area). Do not worry: it is probably nearby. For tips on visiting with a stroller and keeping track of it, check-out this guide.