When we work on Java code we can select for example a property name and each occurrence of this property is highlighted in the code. The following example shows the selection of name in line 7. In line 12 and 22 the occurrences of name are also highlighted.
This is very useful to navigate in source code. Also check out the dark green lines in the right gutter. These also show the occurrences. So in a very large source file, we can use these lines in the right gutter to navigate directly to an occurrence.