I'm very late to answer it. But, I would like to share one example, which I only thought of today. If I told you to cut a piece of paper with dimensions 5m by 5m, then surely you would do that. But suppose I ask you to cut 1000 pieces of paper of the same dimensions. In this case, you won't do the measuring 1000 times; obviously, you would make a frame of 5m by 5m, and then with the help of it you would be able to cut 1000 pieces of paper in less time. So, what you did was make a framework which would do a specific type of task. Instead of performing the same type of task again and again for the same type of applications, you create a framework having all those facilities together in one nice packet, hence providing the abstraction for your application and more importantly many applications.

框架为特定的问题领域提供功能/解决方案。 定义来自wiki:

计算机中的一个软件框架 编程，是一种抽象 哪个公共代码提供泛型 功能可以选择性地 由用户代码覆盖或专门化 提供特定的功能。 框架是一种特殊情况 它们是软件库 代码包装的可重用抽象 在定义良好的应用程序中 编程接口(API)，然而他们 包含一些关键区别 区分它们的特征 普通的图书馆。

一般来说，框架作品是真实的或概念性的结构，旨在作为建筑的支撑或指南，将结构扩展为有用的东西……

在最低的层次上，框架是一个环境，在其中您可以使用一组工具

这些工具以库、配置文件等形式出现。

这个所谓的“环境”为您提供了基本的设置(错误报告、日志文件、语言设置等)……它可以被修改，扩展和构建。

人们实际上不需要框架，这只是想要节省时间的问题，而其他人只是个人喜好的问题。

人们会证明有了框架，你就不必从头开始编码了。但这些只是人们混淆了库和框架。

我在这里没有偏见，实际上我现在使用的是一个框架。

从技术上讲，您不需要框架。如果你想做一个非常非常简单的网站(想想1992年的网页)，你可以用硬编码的HTML和一些CSS来完成。

如果你想做一个现代的网络应用，你实际上也不需要使用框架。

You can instead choose to write all of the logic you need yourself, every time. You can write your own data-persistence/storage layer, or - if you're too busy - just write custom SQL for every single database access. You can write your own authentication and session handling layers. And your own template rending logic. And your own exception-handling logic. And your own security functions. And your own unit test framework to make sure it all works fine. And your own... [goes on for quite a long time]

然后，如果您确实使用了一个框架，您将能够从优秀的、通常是同行评审的、经过很好测试的其他开发人员的工作中受益，他们可能比您更好。您可以快速构建想要的内容，而不必花费时间构建或过于担心上面列出的基础设施项目。

您可以在更短的时间内完成更多的工作，并且知道您正在使用或扩展的框架代码很可能比您自己做得更好。

那么成本呢?花点时间学习框架。但是，正如几乎每个web开发人员都会证明的那样，花时间学习从使用你选择的任何框架中获得大量(真的，大量)好处是绝对值得的。

一个简单的解释是:框架是一个可以围绕它构建应用程序的支架。

A framework generally provides some base functionality which you can use and extend to make more complex applications from, there are frameworks for all sorts of things. Microsofts MVC framework is a good example of this. It provides everything you need to get off the ground building website using the MVC pattern, it handles web requests, routes and the like. All you have to do is implement "Controllers" and provide "Views" which are two constructs defined by the MVC framework. The MVC framework then handles calling your controllers and rendering your views.

也许不是最好的措辞，但我希望它有帮助