Flexible refers to the capability to adjust or bend easily. In the case of shoes, flexible refers to a type of shoe that generally features soft uppers and lightweight, bendable outsoles. Flexible footwear is designed to provide exceptional comfort when worn.
About Slides:
Slides are a sandal in which the upper does not extend to cover the heel of the foot. The wearer of slides can simply slip on the shoe without having to tie, strap, or buckle it to secure.