Welcome in Lightning Web Components Worlds. Here i'm starting the Lightning Web Component series for beginners, this may helps beginners and intermediate level learners to possess an honest knowledge of lightning web components.
Lightning Web Components are announced as part of Spring19 pre-release. As of now, we have built lightning component using the "Aura Components model" we can also built lightning component using the "Lightning Web Components model".
LWC (Lightning Web Components)
For developing LWC we require "Salesforce Extensions for Visual Studio Code" and for deploying LWC from an org we require "Salesforce CLI".
Aura Components make use of own custom component model, custom templates, custom components etc while LWC is built on web standards and it make use of web components, templates, custom elements which we have in web standards. Both Aura component, LWC make use of Security, LDS and Base lightning components.
MIND IT !
1) Aura component and LWC can exist on Same lightning page.
2) Aura component can include LWC