Data Engineering Fundamentals
To me, the fundamentals of data engineering are well described in Fundamentals of Data Engineering Book with the Data Engineering Lifecycle:

Image from the above mentioned book |
Source
If you want to learn related fundamentals, look at Data Engineering Toolkit or Data Engineering Concepts, where I list the most important toolkits for a data engineer and the concepts we need to deal with throughout our career.
# Further Reads
More at:
- Learn the fundamentals as in my book: 📖 Patterns of Data Engineering
- Or find the Data Engineering Vault with 1000 interconnected terms.