A Academic vs General
The general training module is intended to test English ability in a more practical, everyday context. People often take the general training module if they are intending to work or live abroad. The test format, the marking and scoring system is all the same as that of academic. It is generally considered a bit easier than its academic counterpart as the quality of questions is slightly on the lower intellectual scale.
As for the sections, The Listening and Speaking sections are exactly the same for both the papers. However, there are a few subtle changes in the writing and reading sections, such as:
Writing : There are still 2 sections and you will also have to write an essay, but instead of explaining a graph or picture, you will have to write a formal letter requesting information or explaining a situation.
Reading : The reading test is also different to the one for the academic module in terms of the content provided. It is still 60 minutes and there are 40 questions to answer. However, the readings are different as they are based on real life situations rather than being academic.