Footless tights and leggings, the same thing? Actually, no. Although very similar, there are some marked differences between the two, with a few of these summarized below.
Leggings are thought of as a form of trousers, which are sometimes (though not always) acceptable to wear without anything too long covering them. Footless tights, on the other hand, are exactly as they sound, tights without the feet. They should only be worn with long tops or dresses over them, at least if you want to protect your modesty. As with any tights they'll be quite translucent, so never wear footless tights without anything to cover them up.
The difference also lies in the materials that are used to make them. Footless tights are usually made from nylon, often with Lycra added for improved comfort and fit, whereas leggings are made from a thicker cotton material. This not only explains why you need to put something on over the tights, but also means that leggings wear far better and are much more durable because of their thickness.
Leggings are not nearly as delicate as footless tights, and won't tear or ladder under normal circumstances. You can treat them as you would any other pair of trousers you don't have to take particular care when washing leggings or when putting them on, and they'll invariably last a lot longer than their footless counterparts.
Footless tights, on the other hand, are much thinner than leggings, even if they are of a high denier. This means that you will need to take much more care with them if you want to keep them at their best. You should be especially careful when putting your tights on and taking them off, particularly if you have got long nails, as you are highly likely to snag them and rip a hole in them. You should wash them in a delicate cycle using a mild detergent a gentle spin, as they won't be able to withstand the rigors of a normal wash.
Both footless tights and leggings are popular in the fashion of today, but make sure that you choose the right one for your purpose as well as the weather. Footless tights are more suitable in the summer months because they're thinner and cooler, whereas leggings can be more suited to winter use because they're thicker and, subsequently, warmer. While you can get away with the shortest of outfits with both of them, bear in mind that footless tights will not be entirely opaque!
Put simply, leggings are trousers and footless tights are tights. They each have their different specifications, and although often worn interchangeably it is wise to understand the differences between them so you can choose the best one for your outfit.