云厂商提供丰富的应用托管能力，“应用托管”的准确定义是什么？
术语
application hosting
开发者视角的“应用托管”，开发者使用云厂商提供的各种云服务，将应用托管上云。
managed application (hosted application)
企业客户视角的“应用托管”，购买一个“托管”的应用程序。 与订阅SaaS服务不同，在商业模式上，企业客户购买的还是资源+软件，而不是订阅SaaS服务。
Application Infrastructure
Application infrastructure is software platforms for the delivery of business applications, including development and runtime enablers
Application Platform
AWS 官网定义的应用平台：帮助开发者适配云原生技术，以便于加速应用迭代速度，并提供一致的体验。这里的一致的体验，是指在公有云、私有云、混合云不同环境下的一致体验。
Application platforms, such as the Red Hat OpenShift Container Platform and the VMware Tanzu Application Service, help accelerate the adoption of cloud native principles which will accelerate application deployment, enable faster application iteration and provide a unified experience.
Reference
在 Google Cloud 上托管应用 AWS 应用程序托管 Hosting applications on Azure Web Application Hosting in the AWS Cloud Implementing Microservices on AWS Gartner Glossary: Application Infrastructure AWS: Application Platforms Magic Quadrant for Enterprise Application Platform as a Service, Worldwide