Do you still need ECS after using CloudKit? Please tell me, thank you!

Hello, everyone. I'm a newcomer. I want to learn to develop iOS apps. I want to know that the app client is placed on the Apple store and the backend is placed on the cloud server, right? Is CloudKit a backend? How to put it on the cloud server?

Can cloudkit be used as the back end of the app? I want to develop a news app. Can I only use (swiftui + cloudkit)? I am new to develop a app, I hope someone can tell me ,thank you

how to set tabBar on top?

I am a new developer .I want to develop a app, I can develop the front end with SwiftUI ,about the back end service ,can I use CloudKit ? I am in China, I can not use firebase. I hope someone can help me ,thank you

hi ,I am a new developer ,I know use SwiftUI to develop the client ,but how to develop the backend ? app have two part : client and server ,is it right ? I need someone help me . I look forward to your answer.