Layered Basic Learning

Today, the teacher asked me about the progress. The answer is still working on the static template page. The teacher talked about the overall specifications of some projects. He asked me how much I knew about the hierarchy. I answered honestly and didn't know anything about it at all. The teacher gave clear instructions to go back and have a good look at what layer is.
In this way, I have learned the same technology. The stratified technology was designed by the teacher to learn, so I had to study static pages and cache Conversion Technology for the moment.
Ah ~~~ It turns out that I don't know much about it, so I had to read and learn.
I posted a lot of enterprise application architecture models online in English versions. I finally got a photo and print at noon, so I can finally study them happily ~~~~
This essay is not a book note, but I don't think it is easy for the author to understand it. I just translated some of the notes that I can understand ~~~~~~

Chapter 1 of enterprise application architecture model
When breaking down complex software systems, one of the most popular technologies used by software designers is layering. In the computer architecture, we can see examples of layering everywhere.
When we consider the system from a layered perspective, we can think of each subsystem as a multi-layered cake. Each layer depends on its lower layer. However, the upper layer generally does not know the lower layer details.
Advantages of layering:
1. You can take a layer for independent research and development, because the layer and layer are almost non-transparent.
2. You can easily replace a layer.
3. When a layer is changed, the rest will not be easily affected.
4. You can clearly understand the work of each layer of the software system.
5. A layer can be used by many upper layers to reduce repetitive work.
Disadvantages of layering:
1. modification is troublesome. It cannot encapsulate everything.
2. Too many layers will affect performance

The most difficult problem in layered architecture is to decide what to do with several layers and each layer.

When three layers of architecture are used, the presentation layer, the domain layer (also called the business logic layer), and the data source layer are divided.

Performance layer: for example, click a button and a line appears: "Welcome !" This is the responsibility of the performance layer ~~~~
Data Source layer: for example, it is the responsibility of the data source layer to store a piece of news in the database when adding news ~~
Domain Layer: it is used to process complex logic, such as implementing a super paging or a search ~~~