There are two separate breeds of Corgis which are very similar in appearance, the Cardigan Welsh Corgi and the Pembroke Welsh Corgi. The two breeds close resemblance is due to crossbreeding between the Cardigan and Pembroke in the early 1900's. Today the most obvious difference between the two breeds is the Pembroke's lack of a tail (whereas the Cardigan Welsh Corgi has a tail).
The Cardigan Welsh Corgi is a medium sized dog breed which was originally bred in Wales for herding purposes. As with most herding breeds, the Cardigan is highly intelligent and hardworking making them very receptive to training.