Twitter blocked Donald Trump becuase he was using Twitter to incite his suppporters. These then turned violent and stormed the Capitol. The Capitol is a building like our parliament
Twitter he was over 88 million followers the last week she only post a tweet that said that the election was unfair, and that his supporters should protest. His supporters beleived that, and really stared protesting. But in the end they had gone to far, them stormed the Capitol and threatened the politicans and Joe Biden's supporters.
Twitter and Facebook realized that this was too much and dangerous. They banned Trump.
A blackout happens when there is a failure in an electricity network. The electricity supplies are interrupted for in large areas (for ex. In a whole country). A blackout may last from a few minutes up to a few week.
In electricity Networks of the power generation and the electrical demand must be equal at any time of the day. If the power demand is higher than the power generation and overload can occur and damage the components of the power network. As a consequence the electrical supplies interrupted and a blackout happens. To avoid black out the power plants must be controlled so that the produce exactly the amount of electricity that is needed.