The "Touch" cue can be used to move your dog around without physically manipulating them. When we move our dogs for them, they are passive and don't need to think. It is better to teach them to follow cues and do it themselves.
THe hand signal for "Touch" is to present your palm facing your dog, fingers pointed down.
"Touch" is great for getting your dog to step onto the scale at the vet's office. They are more confident if they step on themselves than if they are pushed there.
"Touch" can also be used in place of "Come" if your dog responds better to it. Many dogs find "Touch" more fun than "Come".
For dogs who have a hard time sitting politely for petting, "Touch" can be used to keep them standing still for petting instead.
When we physically move our dog with the leash or collar or by lifting, pulling, or pushing, they are not learning how to how to follow your cues on their own. It's easy to get into that habit instead of communicating with them. Remember to use the cues they've learned instead of doing it for them.