Merge pull request semver#108 from mojombo/clarify-version-comparisons

Clarify version comparisons

Author: haacked

semver.md

@@ -92,14 +92,22 @@ packages with the same version, but different build metadata are considered to
 be the same version. Examples: 1.0.0-alpha+001, 1.0.0+20130313144700, 
 1.0.0-beta+exp.sha.5114f85.
 
-1. Precedence MUST be calculated by separating the version into major, minor,
-patch and pre-release identifiers in that order (Build metadata does not figure 
-into precedence). Major, minor, and patch versions are always compared 
-numerically. Pre-release precedence MUST be determined by comparing each dot 
-separated identifier as follows: identifiers consisting of only digits are 
-compared numerically and identifiers with letters or hyphens are compared 
+1. Precedence refers to how versions are compared to each other when ordered.
+Precedence MUST be calculated by separating the version into major, minor, patch
+and pre-release identifiers in that order (Build metadata does not figure 
+into precedence). Precedence is determined by the first difference when
+comparing each of these identifiers from left to right as follows: Major, minor,
+and patch versions are always compared numerically. Example: 1.0.0 < 2.0.0 <
+2.1.0 < 2.1.1. When major, minor, and patch are equal, a pre-release version has
+lower precedence than a normal version. Example: 1.0.0-alpha < 1.0.0. Precedence
+for two pre-release versions with the same major, minor, and patch version MUST
+be determined by comparing each dot separated identifier from left to right
+until a difference is found as follows: identifiers consisting of only digits
+are compared numerically and identifiers with letters or hyphens are compared
 lexically in ASCII sort order. Numeric identifiers always have lower precedence
-than non-numeric identifiers. Example: 1.0.0-alpha < 1.0.0-alpha.1 < 
+than non-numeric identifiers. A larger set of pre-release fields has a higher
+precedence than a smaller set, if all of the preceding identifiers are equal.
+Example: 1.0.0-alpha < 1.0.0-alpha.1 < 1.0.0-alpha.beta < 1.0.0-beta <
 1.0.0-beta.2 < 1.0.0-beta.11 < 1.0.0-rc.1 < 1.0.0.
 
 Why Use Semantic Versioning?