What is Wesley's concept of Entire Sanctification?

John Wesley believed and taught the doctrine of Entire Sanctification, the idea that it is possible for a believer to achieve perfection in this life, based on Bible verses like: >Those who have been born of God do not sin, because God's seed abides in them; they cannot sin, because they have been born of God. — [1 John 3:9](http://www.biblestudytools.com/nrs/1-john/3-9.html) and Jesus' command: >Be perfect, therefore, as your heavenly Father is perfect. — [Matthew 5:48](http://www.biblestudytools.com/nrs/matthew/5-48.html) Can someone explain what Christian Perfection or Entire Sanctification means?