Words are really important when you’re learning a language. You need them to speak, write and understand things. And the more words you know, the easier it is for you. Even if your grammar is perfect, if you don’t know many words, you’ll find it hard to speak fluently. But not all words are the same.
Some are easy to understand because they’re similar in your language or they remind you of something you already know. For example, “education” is a cognate in many languages (“educación” in Spanish, and “education” in French).