Semver: A Primer

Prefixing a single semver version string with the ^ character defines a range of acceptable versions that include all patch and minor versions from the ones specified up to, but not including, the next version. So "^1.2.3" can be approximately expanded as ">=1.2.3 <2.0.0".

Unlike ~, the ^ operator with a major version of 0 is essentially a no-op, in that it translates to exactly that version rather than a full range. So "^0.2.3" is equal to just "0.2.3" and no more.