Many courses contain 40-50 hours of video content and the amount of data is simply too large to reasonably download. This is also due to propriety issues to prevent course content from being posted on YouTube or various social media platforms.
However, once you have purchased an Online Course you will always have access to it, so you can complete the course whenever you have the required internet connection. Please note, some courses may have supplemental downloads in the form of PDFs or audios, which will be indicated with a "Download" button.