The framework vs. library debate is hot in the programming world. Some people use the words framework and library interchangeably. However, this should not be the case as they are different.
If you are just starting in development, you may not know how to categorize different platforms and tools. For instance, React is a JavaScript library. On the other hand, Angular is defined as a JavaScript framework. However, the two are used to create user interfaces.
Frameworks and libraries are essential tools in the software development realm. Such tools are important in the following ways:
- Provide the building blocks to help you build your programs
- Provide reusable components you can use in your application
- Provide structure for your application
This article will help you learn the differences between a framework and a library, how they work, and their use cases.
What is a Framework?

Frameworks offer a foundation for developers to build applications. Such tools come with high-level components, libraries, reusable code, design patterns, APIs, and toolsets needed to build an application.
Most frameworks follow a specific design philosophy and architectural structure to ensure consistency as developers build applications.
Frameworks may also come with defined and undefined functions and objects. Such features make it easy to add functionality to your application as you edit the code.
A framework will also come with conventions and a toolset that you can use to manage various components of your application, such as business logic, user interface, and data logic.
Why use a framework

- Fast development: You do not need to write all the scripts for your application if you use a framework. Also, some frameworks make it easy to reuse various components to build your applications.
- Offer scalability and flexibility: Frameworks can fit small and large applications. You may start small. However, most frameworks are designed to accommodate your needs as your application grows. You can also change some parts of your application without changing the entire source code.
- Programming sophistication: Some frameworks are designed to make it easy to use ‘hard’ programming languages to build applications.
- Focus on debugging and maintenance: Most programming languages focus on functionality. However, frameworks go a step further to focus on developer experience. Such frameworks come with tools and features that make maintaining and debugging your code easy.
- Improves security: Some frameworks come with built-in security features.
Examples of Frameworks
There exist different frameworks based on different languages. The following are just a few:
Language | Frameworks |
---|---|
Python | FastAPI, Django, Flask, Tornado |
Java | JavaServer Faces, Spring Boot |
Ruby | Sinatra, Ruby on Rails, |
JavaScript | Angular, React, Vue.js, Node.js, Express.js |
Frameworks Use Cases
- Rapid application development: The pre-built functionality of frameworks makes it possible to build apps fast. Some frameworks like Vue.js have built-in features like routing, which reduces development time.
- Provide a common structure: Most frameworks dictate how your app should flow. Such frameworks offer reusable components and ensure you have a consistent app structure.
- Security: Some frameworks have built-in security features that secure your apps.
- Web, mobile, and game development: Different frameworks are created for different niches like web, mobile, and game development.
- API integration: Some frameworks are designed to integrate seamlessly with standard web APIs needed to run applications.
What is a Library?

In software development, a library is a collection of functions you can use to develop your application. A library provides pre-written code that you can use to add special functionality to a program or perform specific tasks.
Libraries are written in specific programming languages to perform specific functions. For instance, React is written in JavaScript and is used to build UIs. Most libraries are modular, meaning their components are split into small, reusable pieces of code.
As a developer, you don’t have to write code for some functionalities from scratch; you can import a library to take care of it. Such libraries allow you to customize the code to suit your needs. However, you can also create a custom library.
Why use a Library?
- Saves time: You don’t have to reinvent the wheel as long as you have libraries. As a developer, pick a library that suits your needs and implement the necessary functionality. You thus get more time to work on implementation rather than common tasks.
- Provides reusable functions: You may write the same code repeatedly. A library can provide reusable functions to call in your application and reduce your app size.
- Provides optimized code: A typical software development process goes through various steps. You must ensure that you test your code and produce optimized applications. Most of the libraries are thoroughly tested and optimized before they are released to the public.
- A variety of libraries to choose from: You may choose between several libraries offering similar functionality. In such a case, look at the documentation, resources, and the community behind such libraries to make an informed decision.
- Decreases development cost: A software engineer earns an average of $51/hour in the US. Libraries provide ready-made solutions that can help you reduce the hours billed when building an application.
Examples of Libraries
Different programming languages have different libraries. These are examples of libraries:
Language | Libraries |
---|---|
JavaScript | Lodash, JQuery, React, D3.js, Underscore.js, Algolia Places, Bideo.js, Chart.js, Anime.js |
Python | NumPy, TensorFlow, PyTorch, Pandas, Keras |
Java | JUnit, Jackson Databind, Guava |
PHP | Swift Mailer, Composer, PHP Mailer |
Libraries Use Cases
- Developing user interfaces: React is a perfect example of a library that you can use to build user interfaces.
- Extend functionality: Some libraries are designed to introduce new functionalities lacking in the core language.
- Specialized tasks: Some libraries implement complex functionalities like simplifying HTTP requests.
- Testing: Code testing is an important step that can be automated using various libraries. For instance, Jest and Mocha are the most popular JavaScript testing libraries.
- Database interaction: Some libraries act as the link between the user interface and the databases.
You may also explore some best JavaScript (JS) UI libraries to build modern applications.
Framework vs. Library
Libraries and frameworks are designed to achieve the same goals (extend the functionality of the core language). However, some, like React and Angular, are used in building UIs even though the former is a library while the latter is a framework. These are some key differences:
Feature | Framework | Library |
---|---|---|
Use | Frameworks can have broad scopes like building web apps, mobile applications and plug-in systems | Libraries are designed for specific tasks such as math operations or form validation |
Control | A framework provides a pre-defined flow and structure. Most frameworks use hooks and callbacks to control structure and flow. | A library provides a set of utilities and functions. However, the developer controls when to call a library and use its functions. |
Scope | Frameworks are restrictive in terms of use. Most of the time, you can only use what belongs to that framework within that framework. | Libraries have a bigger scope. For instance, you can use some JavaScript libraries across frameworks like Next.js and Vue.js |
Purpose | Designed to make it easy to build applications | Designed to provide reusable components for an application |
Extensibility | A framework is designed to be extensible. Such platforms provide app functionality and features you can use in your application without modifying the source code. | A library is designed to perform a specific task and Not be extensible. |
Completeness | Most frameworks are comprehensive, with features like routing and ORMs | Libraries are designed for specific tasks. For instance, if it is a state management library, it only does that. |
Performance | Performance is relative. Some frameworks are big, while others are small. The performance will also depend on the framework’s design and caching. | Performance is relative. It is based on the library’s size and dependencies. |
Replaceability | Replacing a library may mean rewriting the entire code. For instance, you can’t just replace Next.js with Vue.js without making major changes. | You can switch from one library to another at will. For instance, you can switch from Redux to Rematch as your state management library in JavaScript without much struggle. |
Incorporation | A framework is best designed to start a new project. For instance, you can start a new Vue.js project. However, you can not add it to another project created using another framework. | Libraries can be added to existing projects. You can call a library on a particular component. Thus, you don’t have to change the entire codebase to incorporate a library into an existing project. |
Can frameworks and libraries co-exist in an application?

Yes. This is a common practice in software development. A framework provides a foundation or predefined structure that your application will follow. This framework can also come with built-in features like routing and middleware.
On the other hand, you can add libraries to perform specific functions. For instance, you can use a framework like Ruby on Rails as your backend technology. You can use a library/ gem, such as a device, for authentication.
However, you must carefully choose frameworks and libraries and how to integrate them. Over-reliance on libraries and frameworks may result in complexities or conflicts in your application. At times, some libraries are designed to work with specific frameworks.
Conclusion
Based on our discussion, you can comfortably contribute to the framework vs. library debate. Both are developer tools, and they come with pre-written and reusable code.
A library gives you control over where to call it and your application’s direction. On the other hand, a framework gives a predefined set of rules you should follow to build your application. However, it is worth noting that you can use a framework and various libraries in the same application.
You may also explore some amazing frameworks to build internal tools, UI, and admin panels.
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Titus is a Software Engineer and Technical Writer. He develops web apps and writes on SaaS, React, HTML, CSS, JavaScript, Ruby and Ruby on Rails read more
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Narendra Mohan Mittal is a Senior Digital Branding Strategist and Content Editor with over 12 years of versatile experience. He holds an M-Tech (Gold Medalist) and B-Tech (Gold Medalist) in Computer Science & Engineering.
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