What is Lattice deformation?
To add lattice object hit SPACEBAR and select Add -> Lattice. Lattices are grid-like objects which you can assign as parents (ALT + P) to Meshes, Surfaces and Particles. Depending on the position of the lattice vertex’ and it’s shape, the child object is deformed. To permanently assign the deformation, hit SHIFT – CTRL + A. Also try positioning edited lattices in space and move their child object(s) “trough” it.