understand the term instance

[Former Member]

HI all,

I want to understand the term what instance means.this is the definition what i have got

"An Instance is an administrative unit that combines SAP system components providing one or more services.

The services provided by an instance are started and stopped together.

You use a common instance profile to set parameters for all components of an instance.

"

So by this definition does that mean that if we have dev , qual and prod all are ecc based systems then we have 3 instances ?I want to understand what this instance means specifically with respect to SAP.

[Former Member]

Hi

The term u201Cinstanceu201D is often used synonymously with u201Cserveru201D or u201Capplication serveru201D in the SAP system. This depends on the selected installation environment. You can install multiple instances on one application server. It may be thought of as a SAP software concept , used to implement different App. servers in the system landscape.refer: http://help.sap.com/erp2005_ehp_04/helpdata/EN/c4/3a5e90505211d189550000e829fbbd/content.htm

Moreover , A complete SAP system is the set of clients and Application server components that make use of or are assigned to the same database.

Ravi