Twin Size

Yes, twin beds are suitable for adults. A twin is approximately 38 inches wide by 75 inches long, with enough space for most single adults to sleep comfortably. Twins are a great option for anyone with limited space, such as in studio apartments, dorm rooms, or small bedrooms. If you're taller but still need to economize on space, a twin XL, which has the same width but is longer by 5 inches, might be the way to go. However, a twin is generally considered too narrow for two adults, and individual circumstances might lead many to opt for full or queen sizes.

Yes, "twin" and "single" essentially refer to the same size bed. The terms are often interchanged, and it's possible to hear both being used regularly. Whether you call it a twin or a single, the bed we're referring to is 38 inches wide and 75 inches long. Although the size for all single/twin beds is more or less standard, there can be slight variations depending on where you are. For example, while most furniture retailers will distinguish between single/twin and twin XL (the same width but 5 inches longer), others will use "single" and "twin" to make the distinction. Always double-check the dimensions before you buy a new bed. 

A twin bed is usually designed for one person. However, two people could technically sleep on one, provided they don't mind close quarters. Given that a standard twin is 38 inches wide, most adults might find 19 inches insufficient to sleep comfortably with some buffer room to move around. So, while two people can fit and sleep on a twin, it's more likely to be a short-term arrangement.