参见：http://stackoverflow.com/questions/10430043/difference-between-char-and-string-in-java

char is one character. String is zero or more characters.

// char是一个字母，String可以有0个或多个字母（汉字）

char is a primitive type. String is a class.

// char是一个原始类型，String是一个类。

char c = 'a'; String s = "Hi!";

// 这是一个例子，由此可见char里面能放一个字母，String里面可以放多个字母（两个字母+一个符号）

Note the single quotes for char, and double quotes for String.

// char用单引号，String用双引号

// 再附上另外两个答案：

char means single character. In java it is UTF-16 character. String can be thought as an array of chars.

So, imagine "Android" string. It consists of 'A', 'n', 'd', 'r', 'o', 'i' and again 'd'characters.

char is a primitive type in java and String is a class, which encapsulates array of chars.

In layman's term, char is a letter, while String is a collection of letter (or a word). The distinction of ' and " is important, as 'Test' is illegal in Java.

char is a primitive type, String is a class