From BlenderWiki

Translation, Rotation, Scale

Once you have a selection of one or more elements, you can grab/move (G), rotate (R) or scale (S) them, like many other things in Blender, as described in the Manipulation in 3D Space section.

Of course, when you move an element of a given type (e.g. an edge), you also modify the implicitly related elements of other kinds (e.g. vertices and faces).

You also have in Edit mode an extra option when using these basic manipulations: the proportional editing.