Consists of instruction in computer ideas, information systems, networking, working programs, computer hardware, the Web, software functions, help desk ideas and problem solving, and principles of customer support. Many corporations have tried to release electronic studying programs dating back to the early Nineties. On-line retailer Amazon released the Kindle, one of many first to gain a large following among customers. The first Kindle featured wi-fi entry to content material by way of , along with an SD card slot permitting elevated storage. The primary launch proved so widespread there was a protracted delay in delivering methods on launch. Observe-on variations of the Kindle added further audio-video capabilities.