- Scanner: an object that reads input piece by piece
System.in: the keyboard / standard input stream- Read a line with
sc.nextLine()
- File I/O: reading/writing a file on disk — so data can outlive the program instead of being hardcoded
throws Exception: lets the method skip handling errors (bypassing the safer default)- Standard library: It's the core features of a language; comes when you install the language. Ecosystem: All the libraries written by others (huge); must be downloaded separately