Single wallpapers, so you can choose the best ones for your taste. Animated live wallpapers, which all are high quality, at least full HD (1080 x 1920 px). More precise information in the each products description.
You will get a ZIP folder containing the wallpaper and license infos, open / unzip / extract the folder.
When purchased, you will instantly get a secure download link, which will work 24 hours after the first download. Keep your downloaded files safe and secured.
If you are using Android, you can use for example Wallpaper Engine to set a live wallpaper on your home screen. Unfortunately, I have no idea how live wallpapers work on iOS.
Some of the wallpapers may also be available to purchase / download via Zedge App and Walli 4K.