The two versions only differ by the Reading and the Writing parts.
 
The IELTS test is composed of four modules:
 

• Speaking: 15 mins approximately The Speaking component assesses your use of spoken English, and takes approximately 15 minutes to complete and the test is recorded.

• Listening: 30 minutes The Listening part is composed of four recorded texts, monologues and conversations by a range of native speakers. You will have to write your answers to a series of questions as you listen.

• Reading: 60 minutes The Reading component consists of 40 questions. A variety of question types are used in order to test a wide range of reading skills. There is a significant difference between the Academic version and the General version. The Academic version includes three sections taken from books, journals, magazines and newspapers. These sections have been chosen for candidates entering university courses or seeking professional registration. The General version, on the other hand, includes extracts from books, magazines, newspapers, notices, advertisements, company handbooks and guidelines: topics easy to find in the everyday life in an English-speaking environment.

• Writing: 60 minutes The Writing section includes two tasks to be developed. Topics are of general interest (General IELTS) and suitable for candidates entering undergraduate and postgraduate studies or seeking professional registration (Academic IELTS).