The English text scattered through the code is in comments. There are three styles of comments, all illustrated in the Fibonacci example. Comments enable you to write descriptive text alongside your code, annotating it for programmers who may read your code in the future. That programmer may well be you months or years later. You save yourself effort by commenting your own code. Also, you often find bugs when you write comments, because explaining what the code is supposed to do forces you to think about it.
Text that occurs between /* and */ is ignored by the compiler. This style of comment can be used on part of a line, a whole line, or more commonly (as in the example) to define a multiline comment. For single line and part line comments you can use // which tells the compiler to ignore everything after it on that line.
The third kind of comment appears at the very top, between /** and */. A comment starting with two asterisks is a documentation comment ("doc comment" for short). Documentation comments are intended to describe declarations that follow them. The comment in the previous example is for the main method. These comments can be extracted by a tool that uses them to generate reference documentation for your classes. By convention, lines within a documentation comment or a /*...*/ comment have a leading asterisk (which is ignored by documentation tools), which gives a visual clue to readers of the extent of the comment.
