Scalability is the ability of a system to support an increased workload by adding incremental system resources without fundamentally changing the system design or architecture. We must distinguish the scalability from reliability, because reliability is the ability of a system to manage the workload without experiencing failures or stopping altogether.
Checkout my article here, in which I discussed the considerations for SQL Server scalability.
This article is published on SearchSQLServer.techtarget.com.
I wonder where you got the inspiration for this article 😉