Always upgrade to the latest stable revision of your release series.
MongoDB versioning has the form
X.Y refers to either a release series or development series and
Z refers to the revision/patch number.
X.Yrefers to a release series; for example,
3.6release series and
4.0release series. Release series are stable and suitable for production.
X.Yrefers to a development series; for example,
4.1development series and
4.3development series. Development series are for testing only and not for production .
For example, in MongoDB version
3.6 refers to the release series and
.14 refers to the revision.
Changes in the release series (e.g.
3.6 ) generally mark the introduction of new features that may break backwards compatibility.
Changes to the revision number (e.g.
3.6.14 ) generally mark the release of bug fixes and backwards-compatible changes.
The version numbering system for MongoDB differs from the system used for the MongoDB drivers.