I wrote a guest article for an IT consultancy on Azure SQL Database, more specifically DTUs and vCore options. At a high level I discuss what both options are, the differences and what you should select. Hopefully you will find it useful. Please see the link below:
vCore based performance levels are very new, currently in preview and not yet rolled out to all Azure regions (The preview is not available in the following regions: West Europe, France Central, UK South, and UK West.). It does offer a totally different approach to sizing your database.