HA or High Availability is a concept in information technology that indicates the ability of a system or service to provide services to users continuously and with minimal downtime. The main goal of HA is to ensure the stability and availability of the system, even in the event of errors, failures, or scheduled maintenance.

To achieve high availability, various strategies are employed, such as hardware redundancy, distributed task processing, automatic failure detection and recovery, etc. High availability is especially important for critical applications and services, where downtime can lead to serious problems and losses. A similar characteristic is scalability without negatively impacting users. For example, during the national selection for Eurovision, voting took place in the Diia app. High traffic overloaded the Diia servers, causing the app to stop working.