A very detailed intro to backing up SQL Server 2014 by Grant Fritchey:
A backup is nothing more than a copy that is created as a type of insurance
policy in the event that the original goes away. The same applies to SQL
Server database backups to an extent, but database backups are not simply a
file copy. They are a very specific type of copy that is aware of the
transactional nature of SQL Server. This copy will be created in such a way
as to deal with transactions that are ‘in flight,’ that have not yet been
completed. Simply copying the files that define a database will not deal
with transactions and can lead to serious data corruption. For this reason,
you should, in most circumstances, use the native backup processes or, third
party tools that work directly with the native processes such as Red Gate
SQL Backup. There are some large scale systems that will need to work with
non-standard backup mechanisms such as SAN snapshots. These are far outside
the scope of this article.
I was looking for more details about the impact on the databases and how it works with clustered instances so I could compare it with the backup solutions in NoSQL databases.
Original title and link: SQL Server 2014 Backup Basics