PVA glue is polyvinyl acetate glue, your ordinary white glue. Water-based and solvent-free, it is safe to touch and does not smell. However, it could be dangerous when swallowed.
The most common PVA glue is white in color, although you can also find yellow PVA glue which is highly moisturized and has a shorter shelf life than white glue.
PVA glue come in various consistencies and formulas. From wood glue to art-and-craft glues. The more soluble glues are designed for use by children.
Being water-based, PVA glue can be diluted with water for priming any porous surface such as wood, paper or cloth.