# My Learnings from Last Week: ML Fundamentals, Security, and Backend from First Principles

> Source: <https://dev.to/tanay_dwivedi9098/my-learnings-from-last-week-ml-fundamentals-security-and-backend-from-first-principles-bpp>
> Published: 2026-09-21 09:15:00+00:00

Last week, I explored three different areas of technology:

I covered some fundamental concepts, including the three main types of machine learning: **Supervised Learning, Unsupervised Learning, and Reinforcement Learning**.

I also learned about **Exploratory Data Analysis (EDA)** and covered the basics of supervised machine learning, including the **Linear Regression algorithm**.

I covered an overview of how the backend works and learned some of its fundamental concepts, including **domains, subdomains, and the HTTP protocol**.

I covered overview of different types of **Cross-Site Scripting (XSS)** attacks, including **Stored XSS, Reflected XSS, and DOM-based XSS**.

I also took a deep dive into how **Stored XSS** can be used to exploit vulnerabilities and the strategies developers can use to defend against these attacks.