To better understand what CSS is, let's have a closer look at what the abbreviation stands for — Cascading Style Sheets. The word "cascading" implies that styling rules "cascade" down from different levels. In other words, in CSS syntax, the order matters. When style rules have equal specificity, the last rule in a file has a higher priority and overrules the ones listed above it.

For example, imagine you're a designer, and the client sends you a task: "Make the <h1> red." In an hour, they send you an update: "Make the <h1> blue." What color will you set for the headline? The last word has a bigger weight. The headline should be blue. Yes, it has lower precedence, but that's how CSS works.