Online training can provide a cost effective and convenient method of educating people. As well, online learning has been shown to be more effective at teaching material than a conventional classroom, and pupils have increased retention of knowledge. Synchronous online training is done through live-time teaching; whereas, asynchronous teaching has stored material that can usually be accessed at any time. Asynchronous online learning has the additional benefit of being accessed at any time, the ability for the pupil to pick the pace of the material, and the ability to review or skip material as needed. The drawbacks of online learning can be considered to be the cost to purchase the initial technology, the lack of human interaction, and the credibility and accuracy of the material presented.