Question about buying digital off the store

[Dodsy]

Planning on taking advantage of todays cheap thrill but not sure how the whole digital download/ drm thing works. Do I just click the download .pdf and then is it mine to share across all of my devices?
Can I download if as many times as I like from the store or is it a one time only deal?
Cheers for the help 

[Dan Banks]

My experience has been that you can download the file as many times as you want from your "account" page on the shop site and you have access to both pdf and cbz files. It's an excellent service.