# Overview

An ECS is a basic computing unit that consists of vCPUs, memory, OS, and EVS disks.

After creating an ECS, you can use it like using your local computer or physical server, ensuring secure, reliable, and efficient computing. ECSs support self-service creation, modification, and operation. You can create an ECS by specifying its vCPUs, memory, OS, and login authentication. After the ECS is created, you can modify its specifications as required. This ensures a reliable, secure, efficient computing environment.

The cloud platform provides multiple ECS types for different computing and storage capabilities. One ECS type provides various flavors with different vCPU and memory configurations for you to select.

- For details about ECS types, see ECS Types.
- For details about all ECS statuses in a lifecycle, see ECS Lifecycle.
- For details about ECS specifications, see ECS Specifications.

Parent topic: Instances