what does compare do in java code example

Example 1: string compare java ==

// These two have the same value
new String("test").equals("test") // --> true 

// ... but they are not the same object
new String("test") == "test" // --> false 

// ... neither are these
new String("test") == new String("test") // --> false

Example 2: compareto method java

public int compareTo(Jedi jedi){
    return this.age > jedi.age ? 1 : this.age < jedi.age ? -1 : 0;
}