Regex expressions in Java, \\s vs. \\s+?

What's the difference between the following two expressions? x = x.replaceAll("\\s", ""); x = x.replaceAll("\\s+", ...

Regex expressions in Java, \\s vs. \\s+?

What's the difference between the following two expressions? x = x.replaceAll("\\s", ""); x = x.replaceAll("\\s+", ...