DDoS
According to the most general classification, technical attacks can be carried out either without direct access to the server or with the need of access to the server. In the first group are mostly incidents whose most important goal is to prevent access to the content of the site.
There are several ways to crash a server, and the most commonly used is a DDoS (Distributed Denial of Service) attack. This means that a huge number of devices simultaneously send access requests to the attacked server, which cannot answer all the queries and simply stops working. After the attack stops, in most cases the server and the site work normally.