Hi Nesa!
You can find more information on the ACSA including learning resources here: https://www.arubanetworks.com/support-services/training-services/certified-switching-associate/
As you can see there are several options...
VILT= more expensive option, 3 day course, and you get a top-notch Aruba instructor who you can ask questions to and interact with your peers in class.
WBT= less expensive option, you watch the eLearning videos on your own time and have two days to practice the lab exercises on your own (with email lab support available).
I don't think either option is best, it depends on the student and your preferred learning style/ budget/ time constraints. The curriculum is exactly the same in both formats.
If you have any other questions or need help with registering contact us at arubatraining@hpe.com