
Service Models, Digital Ocean
The Three Service Models
1.
Software as a Service (SaaS) (eg. Microsoft 365, Salesforce CRM, Slack, Dropbox)
2.
Platform as a Service (PaaS) (eg. AWS Lambda, Google App Engine, Heroku)
3.
Infrastructure as a Service (IaaS) (eg. Amazon EC2, Google Compute Engine, Microsoft Azure)

Digital Ocean
ns1.digitalocean.com
ns2.digitalocean.com
ns3.digitalocean.com
A Type
Hostname: @ > Will directo to: Droplet(IP)
CNAME Type
Hostname: www > Will directo to: @(domain)
A Type
Hostname: subdomain (subdomain.domain.com) > directs to: Droplet(IP)
Microsoft Azure
Active Directory vs Azure Active Directory (AD Connect)
ExpressRoute
Virtual Desktop
DevOps
Networking
Amazon Web Services (AWS)