When you create type, a new type layer is added to the Layers palette.
After you create a type layer, you can edit the type and apply layer commands to it.
Once you make a change to a type layer that requires it to be rasterized, however, Photoshop converts the vector-based type outlines to pixels. Rasterized type no longer has vector outlines and is uneditable as type. See Rasterize type layers.
You can make the following changes to a type layer and still edit the type:
Change the orientation of type.
Apply anti-aliasing.
Convert between point type and paragraph type.
Create a work path from type.
Apply transformation commands from the Edit menu, except for Perspective and Distort.
Use layer styles.
Use fill shortcuts (see Keys for painting objects).
Warp type to conform to a variety of shapes.