Web Farm and Web Garden - Better performance of website

Web Farm:

When you are hosting your single web site on multiple web servers over load balancer is called “Web Farm”

In a single statement, when we host a web application over multiple web servers to distribute the load among them, it is called Web Farm.

Web Garden:

Now, by default, each and every Application pool contains a single worker process. Application which contains the multiple worker process is called “Web Garden”.


For Read more:
https://www.codeproject.com/Articles/114910/What-is-the-difference-between-Web-Farm-and-Web-Ga

Multi Tenancy

Multitenancy:
                      Multitenancy is an architecture in which a single instance of software runs on a server and serves multiple tenants. A tenant is a group of customers who share a common access with specific privileges to the software instance.

Each customer shares the same application and also shares a single database or load single database  based on logged in customers.