What is Flask?

Flask is a lightweight, free tool that helps you build web sites and web apps using the Python programming language. It gives you the basic pieces you need, but lets you add extra features only when you want them.

Let's break it down

  • Lightweight: Small and simple, not packed with a lot of built-in stuff.
  • Free tool: Open-source software you can download and use without paying.
  • Build web sites and web apps: Create pages you can visit in a browser and programs that run on the internet.
  • Python programming language: A popular, easy-to-read coding language that many beginners learn first.
  • Basic pieces: Core parts like handling URLs, sending responses, and managing templates.
  • Add extra features only when you want them: You can install extra libraries (called extensions) for things like databases or user login, but you don’t have to use them if you don’t need them.

Why does it matter?

Flask lets beginners start making real, interactive web projects quickly without getting overwhelmed by complex settings. It also scales up, so the same code can grow into larger applications as you learn more.

Where is it used?

  • Small personal blogs or portfolio sites where the owner wants full control over design.
  • Prototypes and demos for startups to test ideas before building a full product.
  • Internal tools at companies, such as dashboards that show data from databases.
  • Educational platforms that teach coding, because Flask’s simplicity makes it easy to illustrate web concepts.

Good things about it

  • Very easy to learn; you can have a “Hello, World!” page in just a few lines of code.
  • Flexible - you choose the libraries and structure that fit your project.
  • Large community and many extensions for common needs (e.g., authentication, databases).
  • Works well with other Python tools, making it great for data-science or machine-learning web apps.
  • Good documentation and many tutorials aimed at beginners.

Not-so-good things

  • Because it’s minimal, you have to decide and set up many things yourself, which can be confusing for absolute beginners.
  • Not as many built-in security features as larger frameworks, so you must add them manually.
  • May become harder to manage as the project grows very large, requiring extra organization or switching to a more opinionated framework.
  • Limited built-in admin interface, so creating back-office pages takes extra work.