What are the basic differences among SAP Business ByDesign, SAP Business One and MySAP All-in-One??

kindly refer the below para for the answers taken from authentic SAP online help.

mySAP is the new branding of solutions provided by SAP. I'd say the initiative launched probably sometime in Year 2000. But recently a number of organizations have licensed out either the complete mySAP.com suite of products or individual solutions from within this suite. The solutions that fall under this suite of products have to be licensed separately from your existing SAP R/3 solution. If you're unfamiliar with SAP R/3 -- R/3 has been implemented in a large majority of the fortune 100-500 organizations globally. It is an ERP solution that provides functionality for your Financials, Logistics, Supply Chain, Human Resources and Enterprise Reporting all providing a holistic view of your enterprise operations.

 the difference between SAP Business One and SAP R/3. The non technical answer to this question is that; SAP Business One is SAP's offering for small and mid size companies, while R/3 is SAP's offering for large companies. This is especially true functionality-wise. More to it, the system architecture differs considerably and that hopefully supports the difference in functionality complexities (of SAP R/3 when compare with SAP Business One).

SAP Business One is a software that was bought over by SAP and it has been greatly enhanced over time, however, not much has been done to its architecture. SAP R/3 is indigenous to SAP and it has also undergone various re-engineering over time, especially as it relates to its architecture. A fantastic testimony to this position is in the architecture of its successor, SAP ECC.