Javascript is not like Java, they're both completely different languages! Javascript is used website development (web dev). In web dev Javascript is like the electrical or plumbing work inside your house, everything looks nice with html & css but not functional to live in. Now if you would like to use JavaScript you can! its built into your Operating System (at least on Windows 11)
In Javascript you dont really have a terminal, but you do have something similar; a console. In most browsers if you right click and "inspect" that will take you to the console. It is also quite important to note that Javascript can use semicolons but doesn't have too.
console.log("hello world");
Variables are like a storage locker for a type of data
let