CodeIgniter is a robust open-source software framework for building dynamic websites with PHP. It provides a rich set of libraries for commonly needed tasks and a simple interface and logical structure to access these libraries. Here are some key points to remember about CodeIgniter:

Pros:
1. Lightweight: CodeIgniter is known for its lightweight and minimalistic approach, making it easy to set up and use. It does not require a steep learning curve, making it ideal for developers of all skill levels.
2. Speed: The framework is known for its speed and performance, allowing developers to build efficient web applications, which is particularly beneficial for projects that require quick turnaround times.
3. Good Documentation: CodeIgniter’s comprehensive and well-organized documentation makes it easier for developers to understand and utilize its features.
4. MVC Architecture: It follows the Model-View-Controller (MVC) architecture, which promotes the separation of concerns and makes the code easier to manage and maintain.
5. Active Community: CodeIgniter has a large and active community of developers, which means that there are plenty of resources, tutorials, and add-ons available for support.

Cons:
1. Limited Built-in Features: Compared to some other frameworks, CodeIgniter has a more limited set of built-in features. Developers may need to rely on third-party libraries or write custom code for specific functionalities.
2. Fewer Updates: While CodeIgniter’s lightweight nature is a benefit, it also means that updates and new feature releases may not be as frequent as with some other frameworks.
3. Less Opinionated: CodeIgniter is less opinionated than other frameworks, meaning developers have more freedom in structuring their code. While this can be a pro for some, it can also lead to inconsistencies in larger development teams.

In conclusion, CodeIgniter is a versatile and efficient framework for building web applications with PHP. Its lightweight nature, speed, and robust community make it a popular choice for developers looking to create dynamic websites quickly. While it may have some limitations regarding built-in features and updates, it remains a strong contender in PHP frameworks.