SAP Business Suite is an umbrella term provided to a bundle of five software applications known as SAP ECC (SAP ERP Central Component), SAP CRM (Customer Relationship Management), SAP SRM (Supplier Relationship Management), SAP SCM (Supply Chain Management) and SAP PLM (Product Lifecycle Management).

Let’s take a huge organisation like Apple as an example. They will require software to manage their finances, run payroll and perform other resource planning activities for which they can use SAP ECC. They have to take care of their customers (SAP CRM), manage their suppliers (SAP SRM), ensure their supply chain is efficient (SAP SCM) and develop products (SAP PLM).
All these applications can be tightly integrated not just from a technical perspective but also from a business process perspective so that there is a seamless flow of information across multiple departments.

A minimum version or enhancement pack level is required as a pre-requisite if these applications need to run on the SAP HANA database. For example, the minimum required version of SAP ECC to run on HANA DB is EHP 7. For other applications such as CRM, SRM, SCM and PLM, the minimum version required to run on HANA DB is 7.0.
P.S. Check out my course on Udemy – “Introduction to SAP – The Complete Package for Beginners“