What is the difference between grievous bodily harm and actual bodily harm?

In English law, there is a range of non-fatal offences regulated by the Offences Against the Person Act. The offences are of varying degrees of severity beginning with 'common assault' (the least serious), 'assault occasioning actual bodily harm' (ABH), and the most serious 'assault occasioning grievous bodily harm' (GBH). Surface injuries, such as bruises and grazes, fall within the category of ABH, while more serious injuries, such as broken bones, are categorised as GBH. Examples of ABH: loss or breaking of teeth temporary loss of sensory functions extensive or multiple bruising minor fractures and cuts requiring stitches psychiatric injury going beyond fear, distress or panic Examples of GBH: injury resulting in some permanent disability or visible disfigurement broken or displaced limbs or bones injuries requiring blood transfusion or lengthy treatment