A crack is a modification or patch that enables a software to be used without a valid license or activation. In the case of Adobe Photoshop CC 2017, a crack would allow users to bypass the software's activation process, making it possible to use the software without purchasing a subscription.
For those specifically interested in "cracked" effects for design, Adobe provides tutorials on creating a broken glass effect or distorted text using standard Photoshop tools. photoshop cc 2017 crack youtube