This video reviews String methods:

-- .equals() which compares two Strings, returning true if they are the same and false if they are different. 

--.length() which returns the length of a String

--.charAt() which returns the character at a specific place in the String

This video goes over the two different substring methods that Strings have. 

The substring methods remove pieces from a String. 

To concatenate or squish Strings together and make a new String you don't need any methods, you can just use the + operator.

Example: 

String wordOne = "sun";

String wordTwo = "flower";

String word = wordOne + wordTwo ;

System.out.println(word);

Will print: sunflower