Framework vs. library: main differences and examples

By Indeed Editorial Team

Published 5 September 2022

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

If you're a relative novice who wishes to begin a career in programming, you may benefit from understanding the differences between frameworks and libraries. Though both options can greatly reduce the time required to build new applications, they include varying technical features and solve different programming problems. By reading the guide, you can more easily judge which option best suits the technical specifications laid down in your software development brief. In this article, we define framework and library, detail six key differences between these concepts and provide real-world examples.

What are frameworks and libraries?

Frameworks provide foundations that software developers may build on to develop high-quality applications. These systems outline the parameters inside which extra programming occurs and integrate minor functions to create workable new software. You can't modify such parameters' base code when creating an application, though you may complement them with extra layers of code. Depending on your project's specifications, you can source framework solutions from commercial developers or open-source projects. Commercial providers typically offer superior security features and technical support, though open-source projects give application developers more influence over future framework updates.

Libraries contain a series of pre-coded functions designed to carry out specific tasks. When developing a new application, you can integrate these functions directly into the final code, allowing you to provide tested solutions for regular coding issues. By using pre-coded features, you can ensure that finished applications only include functions required to provide an efficient and reliable user experience, minimising functional errors. You may also limit the presence of poor code within applications by using pre-tested functions. Function libraries may contain many types of pre-coded functions, such as configuration data, documentation and subroutines.

Related: FAQ: what is JavaScript?

Framework vs. library

The section lists six key differences between a programming framework vs. library:

Adaptability

One key difference between frameworks and libraries concerns adaptability. You may alter pre-written library code to help functions smoothly integrate into an application's foundational code. You may also adapt the functions' code later to boost performance or adapt documentation instructions. In contrast, frameworks include fixed foundational code which you can't modify, though the code can change if its original developers decide to update it.

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Inversion of control

Another contrast between frameworks and libraries concerns the inversion of control. If you're using libraries to source pre-coded functions, you could control the workflow required to develop applications without input from the library itself. You can choose which functions to integrate into an application's overall code, when to integrate them and for what purpose. In contrast, frameworks can control the application's workflow without requiring external input. Though you can enter additional code to develop and customise function templates, the framework decides when to request code for integration into the application.

Performance

As libraries only include the code required to execute certain independent functions, you can load them fairly quickly. Better performance allows you to access and integrate useful functions in short order, reducing total development costs. Contrastingly, frameworks contain significant quantities of complex base code, which can increase loading times and slow the application development process.

Scalability

Libraries provide several options to scale up existing projects, whereas frameworks largely offer foundations for developing new applications. Using libraries, you might integrate extra functions into existing applications to increase performance or improve user experiences. For example, if you're upgrading an instant messaging application, you may integrate newly-created 'Reaction' button functions to allow users to customise message responses. In contrast, you cannot integrate frameworks into existing systems as their coding structures may conflict with the application's original base code.

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Niche vs. generalist

Libraries usually include niche functions created to serve certain purposes, whereas frameworks offer broad-based coding solutions. As library functions execute small tasks, they have limited practical relevance beyond this niche area. Conversely, frameworks provide the base code that developers use to build new applications and link together different functions. Frameworks may perform a broader range of tasks, though developers can use niche framework types to build certain applications. For example, you can use front-end frameworks to develop user interfaces and back-end frameworks to link together data processing functions.

Related: Front end vs. back end in web development (plus skills)

Replacing code

Another key difference between libraries and frameworks concerns the ease of replacing existing code. Using libraries, you may replace functions from one library with code from another if you feel that the latter option provides a smoother user experience. For example, if a library's 'Reaction' button functions only offer limited reaction options, you can source a similar yet more comprehensive function from another library. In contrast, you cannot replace parts of a framework's code without entirely rewriting the application's base code.

Examples of frameworks

The section below provides three examples of programming frameworks:

Bootstrap

Bootstrap is a free front-end programming framework that you could use to create high-quality websites that function efficiently across several devices. The framework contains a series of basic templates that you might use to create custom text, buttons or image placement, writing additional code to convert the templates into workable functions. Bootstrap supports four coding languages, including HTML, CSS, Less and Sass. It can also support optional Javascript plug-ins, which you can use to add new functions to software without altering the existing code. Bootstrap also has a responsive grid system consisting of pre-defined blocks that you fill with content.

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Ruby on Rails

Ruby on Rails is an open-source back-end framework that blends the coding language Ruby and Rails, a large software library. You can use this service to create web products with compact code, allowing you to scale up existing functions in accordance with agile principles. Ruby on Rails uses the Model, View and Controller web architecture model, which splits functions' code into several layers, such as the data layer, presentation layer and resource layer. This system also uses the Active Record library, which you can employ to design database interaction queries. The service's RSpec solution can test new functions.

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Django

Django is a free open-source framework that uses Python to handle the entire process of producing compact web applications. This service includes an object-relational mapper tool that you could use to translate your desired database layout into Python. You may also use Django's data-model syntax tool to notice key insights about your data values' behaviours and parameters. Django provides various template HTML forms that you can use to validate or update inputted data before translating it for use by Python. Another key feature is the tool's automatic admin interface, which interprets metadata to build useful content management interfaces.

Examples of libraries

The section below lists three examples of programming libraries:

ReactJS

ReactJS is a front-end open-source function library that you could use to create high-performing and intuitive user interfaces. This system uses the 'render()' method to interpret input data and choose the information to display on every user's device. You may view data displayed on user interfaces using 'render()' via 'this.props'. ReactJS follows the declarative programming paradigm, which programmes functions by stating their desired outcome. You may then build webpages representing the application's state at a certain moment. ReactJS updates these pages when data values change.

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JQuery

JQuery is a programming library that includes pre-coded functions written in JavaScript. This library may build functions operational across multiple laptop and mobile phone browsers. JQuery also arranges data values via the Document Object Model, which depicts HTML documents as tree diagrams with connected leaves and nodes. You could access values in HTML tree diagrams using Sizzle, a JavaScript selector engine that attributes an identifying string to all values. JQuery includes options to build asynchronous applications using Ajax. For example, you may use $.ajaxSetup() to set default values for later Ajax requests.

Pillow

Pillow is a free open-source functions library that allows you to design bitmap images written in Python code. Using this tool, you can use the 'Image Class' feature to create new instances designed to either load or process existing images or create entirely new images. You might convert coded files into JPEG images or thumbnails using the 'save()' option, while the 'crop()' method provides options to copy, process and re-paste the images' subrectangles.

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