An advanced level of understanding of computers means that you have the knowledge and skills to perform highly sophisticated tasks on a computer, such as:
Designing, developing, and testing software applications and systems
Using different programming languages and paradigms to solve complex problems
Applying advanced algorithms, data structures, and design patterns
Working with big data, artificial intelligence, and machine learning
Developing web, mobile, and cloud-based applications and services
Using various tools and frameworks for software engineering and development
Implementing security, encryption, and authentication techniques
Optimizing performance, efficiency, and scalability of software systems
Debugging, testing, and deploying software systems
Documenting and maintaining software systems
These skills are essential for using a computer for research or innovation purposes. They can also help you pursue a career or further education in computer science or related fields.
If you want to improve your advanced computer skills, there are many online resources that can help you. For example, you can check out the following:
Advanced Programming course from the University of York
MSc Advanced Computer Science programme from the same university