A basic frogtie places the person thus tied in a position where they are vulnerable but not completely immobilised; in particular, they can still move about, but very awkwardly, in a crawling motion.
The frogtie can be used as a basis for far more restrictive bondage.
A simpler version of the frogtie simply ties each wrist to its corresponding ankle. This is less stringent than the full frogtie.
Another variant is to tie the ankles to the thighs and then tie the hands together behind the back, often in a box tie.