A life cycle model is also known as a process model. As the name suggests, the software life cycle model (or the software process model) gives us a pictorial representation of the entire software development process.

生命周期模型也稱為過程模型 。 顧名思義， 軟件生命周期模型 (或軟件過程模型 )為我們提供了整個軟件開發過程的圖形表示。

The life cycle model deals with each phase of the software development process and includes all the activities that are involved in its life cycle, i.e. from the initial phase (the ideation phase) of the software to its retirement phase (when the software is no longer under useful). The life cycle model involves each of these activities in the same order in which they are performed and it also takes special take care of the flow in which each activity will be carried out. This flow that is defined in the model cannot be broken while developing the software.

生命周期模型處理軟件開發過程的每個階段，并包括其生命周期中涉及的所有活動，即從軟件的初始階段(構想階段)到其淘汰階段(不再使用軟件時)下有用)。 生命周期模型以執行它們的相同順序涉及這些活動中的每一個，并且還特別注意將執行每個活動的流程。 在開發軟件時不能破壞模型中定義的流程。

為什么在軟件開發中需要軟件生命周期模型？ (Why do we need a software lifecycle model in software development?)

To work according to the software engineering principles, choosing a software lifecycle model for the software in the initial phases itself is must so that the developers can have an idea about when to start and terminate each of the activities in software. Having a lifecycle model for the software would help the developers to develop the software in a systematic and organized manner.

要根據軟件工程原理工作，必須在初始階段為軟件選擇軟件生命周期模型，以便開發人員可以了解何時啟動和終止軟件中的每個活動。 為軟件擁有生命周期模型將有助于開發人員以系統和有組織的方式開發軟件。

Through the software lifecycle model, we get an overview of the sequence of activities in which they are carried out. We get to know if we can return back to the previous activity for making any sort of changes after we have proceeded to the next activities. By knowing this, we can draw an estimate what should be our strategy to proceed and what are the update and change options that are available to us after we have started the development process of the software.

通過軟件生命周期模型，我們可以大致了解執行這些活動的順序。 我們知道在繼續進行下一個活動之后是否可以返回上一個活動進行任何更改。 通過了解這一點，我們可以估算出應該采取什么策略，并在開始軟件開發過程后可以使用哪些更新和更改選項。

軟件生命周期模型的類型 (Types of software lifecycle models)

There are numerous lifecycle models that are known to us, and each of them has their own activities flow order, and each of them differ from each other in some manner. Each of them has some pros and cons over other models. Some of the widely known lifecycle models that are commonly used are:

我們知道許多生命周期模型，每個模型都有自己的活動流程順序，并且每個模型在某種程度上彼此不同。 他們每個人在其他模型上都有優點和缺點。 一些常用的生命周期模型是：

1. Waterfall Model

   瀑布模型

   1. Classical Waterfall model古典瀑布模型
   2. Iterative Waterfall model

2. Prototyping model

   原型模型

3. Evolutionary model

   進化模型

4. Spiral model

   螺旋模型

翻譯自: https://www.includehelp.com/basics/software-life-cycle-model-and-its-types.aspx