An ECS instance is a virtual machine that contains basic computing components such as the CPU, memory, operating system, and network. You can fully customize and modify all configurations of an ECS instance. After logging on to Alibaba Cloud Management Console, you can manage resources and configure the environment of your ECS instances.
ECS instances are categorized into different instance families based on the business scenarios to which instance families can be applied. You can select current and previous instance families for a business scenario. An instance family also has many instance types based on different CPU and memory configurations. An ECS instance defines two basic attributes: the instance CPU and memory configuration (including the CPU model and clock speed). For more information about instance types, see Instance families and Phased-out instance types. If the instance configuration does not suit your application requirements, you can change the instance type. For more information, see Overview of configuration changes.
For more information about the billing methods and prices of ECS instances, see Billing overview.
For more information about the limits and quotas of ECS instances, see Limits.