TL;DR. TL;DR, short for too long; didn't read, is Internet slang to say that some text being replied to has been ignored because of its length. It is also used as a signifier for a summary of an online post or news article. The phrase dates back to at least 2003, and was added to the Oxford Dictionaries Online in 2013.
Ugg boots (sometimes called uggs) are a unisex style of sheepskin boot originating in Australia and New Zealand. The boots are typically made of twin-faced sheepskin with fleece on the inside, a tanned outer surface and a synthetic sole. The term, ugg boots, originated from Australia, initially for utilitarian footwear worn for warmth, and which were often worn by surfers during the 1960s. In the 1970s, the boots were introduced to the surf culture of the United Kingdom and the United States.
Diffusion of Innovation Theory. Diffusion of Innovation (DOI) Theory, developed by E.M. Rogers in 1962, is one of the oldest social science theories. It originated in communication to explain how, over time, an idea or product gains momentum and diffuses (or spreads) through a specific population or social system. The end result of this diffusion is that people, as part of a social system, adopt a new idea, behavior, or product. Adoption means that a person does something differently than what they had previously (i.e., purchase or use a new product, acquire and perform a new behavior, etc.).