Traditionally, labour is divided into 3 stages.
The First stage is from onset of labour until the cervix (neck of the womb) is fully open or fully dilated. The length of the First Stage can vary very greatly, but for the average first time labour, this will consist of 10-14 hours of strong, regular, frequent and usually painful, contractions.
For subsequent labours this is usually much quicker and on average will last 6-8 hours. This stage includes both Latent Labour and Active Labour. These will be explained below.
The Second Stage is defined as being from the cervix being fully open until the delivery of the baby. Again this can vary greatly but in first time mothers this would last anywhere between half an hour to 2 hours.
In subsequent deliveries this is unlikely to be more than one hour and in some cases can be considerably quicker.
The Third Stage is from the delivery of the baby until delivery of the placenta and this will usually last less than 20 minutes.
The total duration of labour varies enormously and often has an unpredictable course.
First labours are generally longer and more difficult than subsequent labours.
Read about the following Stages of Labour