Azure Websites
Azure Websites are fully managed containers to run Web Applications and
Sites. Azure Websites are not Azure hosted Windows Servers with the Internet
Information Services (IIS) role installed, Azure Websites are
Platform-as-a-Service (PaaS) thus Microsoft manage all of the under lying
infrastructure that serve your websites and applications.
Azure Websites can be created using the Azure PowerShell SDK, the Azure
Management Portal or the X-Plat CLI tools. When you create a new Azure Website
you must specify the following;
- A unique URL for the website/application at .azurewebsites.net
- An App Service plan
- A pricing tier
- A resource group
- A subscription to link it to
- A location for the website to reside
Figure 1: Summary of new Azure Website
Azure Website Pricing and Resource Tiers
Azure Websites are available in four different tiers, each of which offer
different amounts of resources and consumables that are available to the
application or website.
The tiers are Free, Shared, Basic and Standard. Microsoft generously offer
an entirely free Azure Website tier which can be used to host simple websites
and applications, although this has some limitations such as a maximum daily
bandwidth limit of 165Mb’s. As the tiers increase so does the price, but with
this you’re Azure Websites are given more resources on the underlying Azure infrastructure.
The Free and Shared tiers both run on shared VM instances under the covers,
but the Basic and Standard tiers have dedicated instances for any applications
or websites being hosted. It should be noted that there is no interference between
tenants who are potentially sharing a VM instance for example to host their web
application.
Furthermore the Free and Share tiers only have a single instance tier,
whereas the Basic and Standard come with three instance types for example B1,
B3 and S2 for example, each of the resources for that instance increase. 
Figure 2: Overview of the
Resources Available for S1 and B1
Enhancements such as
built-in load balancing is also included with the Basic and Standard tiers, whereas
this is not available for Free or Standard.
Figure 3: A Comparison between Basic and Standard
Tier Instance Types
Data transfers for Azure are fairly standard across the board, inbound data
transfers are not changeable but egress traffic from the Azure data centers is
charged at a per GB/TB rate, the first 5Gb’s outbound is free across all zones.
You can read more on this at the following site as it’s likely to change http://azure.microsoft.com/en-gb/pricing/details/data-transfers/
Azure Website Quotas, Limits and Constraints
Most of the services that are available in Azure have two limitations, a default limitation and an ultimate (or hard) limit. The default
limitation is the soft limit in which Microsoft has set on a service, this
governs the amount of resources that is available to a given “stock service”.
This default limit can normally be increased if you approach Microsoft with a
valid reason and use case as to why you want it increase. The ultimate limit on
the other hand is the maximum limit that is available to a given resource,
Microsoft cannot expand this limit.
Figure 4: Web Applications Limits
https://azure.microsoft.com/en-gb/documentation/articles/azure-subscription-service-limits/#subscription-limits
https://azure.microsoft.com/en-gb/documentation/articles/azure-subscription-service-limits/#subscription-limits