SAP - ERP

 SAP - ERP 

SAP AG  is a German software corporation that makes enterprise software to manage business operations and customer relations.

SAP was founded in June 1972 as Systemanalyse und Programmentwicklung ("System Analysis and Program Development") by five former IBM engineers in Mannheim, Baden-Württemberg (Dietmar Hopp, Klaus Tschira, Hans-Werner Hector, Hasso Plattner, and Claus Wellenreuther). The acronym was later changed to stand for Systeme, Anwendungen und Produkte in der Datenverarbeitung ("Systems, Applications and Products in Data Processing").

In 1973 the SAP R/1 solution was launched. Six years later, in 1979, SAP launched SAP R/2. In 1981, SAP brought a re-designed product to market. However, SAP R/2 did not improve until the period between 1985 and 1990. SAP developed and released several versions of R/3 in 1992.

History in details : http://en.wikipedia.org/wiki/SAP_AG

 SAP R/3

SAP stands for Systems, Applications and Products in data processing 

R/3 Stands for
R = REAL TIME
3 = THREE - TIRE ARCHITECTURE

Three-tier architecture has the following three tiers: 

1. Presentation tier

This is the topmost level of the application. The presentation tier displays information related to such services as browsing merchandise, purchasing, and shopping cart contents. It communicates with other tiers by outputting results to the browser/client tier and all other tiers in the network.

2. Application tier (business logic, logic tier, data access tier, or middle tier)

The logic tier is pulled out from the presentation tier and, as its own layer, it controls an application’s functionality by performing detailed processing.

3. Data tier

This tier consists of database servers. Here information is stored and retrieved. This tier keeps data neutral and independent from application servers or business logic. Giving data its own tier also improves scalability and performance.

Ref :- wikipedia