Hey guys i need your help tell me the names of a few common classes to be imported in a program by oracle for us to use

Question

Following java course on sololearn i got to know that there are a few classes by java which we can use to import in our own classes and they perform some task
like
import java.awt.* etc
share your knoledge about this below
thanks

Answer 1

Some cool classes that you can import (no-ui)
~ in course ~
java.util.ArrayList:
java.util.LinkedList
java.util.Scanner
java.util.HashMap
java.util.HashSet
java.io.file
java.util.Formatter
~ Not in Course ~
java.util.TreeSet
java.io.BufferedReader
java.math.BigInteger
java.io.FileWriter
java.io.FileReader
java.net.URL
java.util.Date
java.text.DecimalFormat
java.lang.Reflect
java.lang.Proxy
java.util.Concurreny
java.lang.Class
java.util.Random <-- Try playing with this
java.util.SecureRandom
java.util.Collections <-- and this

All classes:
https://docs.oracle.com/javase/8/docs/api/allclasses-noframe.html

Answer 2

can you define their functions please
the link you posted is too long and nothing informative can be found there so.. please reply