USMLE stands for United States Medical Licensing Exams, and is divided into 3 Steps which test different stages of medical education and training.

Step 1tests the basic sciences and their clinical correlation , which is equivalent to the first 3 years of medical school


Step 2 is divided into 2 parts : CK ( Clinical Knowledge ) and CS ( Clinical Skills). This step tests the clinical sciences and the guidelines set for the management of the different medical disorders . It also tests the correlation of these clinical sciences with the basics sciences , although less extensive than in step 1. The CS portion is different from CK and tests the clinical skills , the interpersonal and communication skills as well as the spoken English of candidates.


Step 3 is the final step that test the ability to practice unsupervised medicine and take management decisions in a logical and accepted manner according to the set guidelines.

Source: eamtar.com