Enterprise resource planning
Enterprise resource planning (ERP) is the integrated management of main business
processes, often in real-time and mediated by software and technology.
ERP is usually referred to as a category of business management software — typically a suite of
integrated applications—that an organization can use to collect, store, manage, and interpret
data from these many business activities.
Customer relationship management
Customer relationship management (CRM) is an approach to manage a company’s interaction
with current and potential customers. It uses data analysis about customers’ history with a
company to improve business relationships with customers, specifically focusing on customer
retention and ultimately driving sales growth. 
Electronic billing or electronic bill payment and presentment, is when a seller such as
company, organization, or group sends its bills or invoices over the internet, and customers pay
the bills electronically.  This replaces the traditional method where invoices were sent in paper
form and payments were done by manual means such as sending cheques.
Accounting software describes a type of application software that records and
processes accounting transactions within functional modules such as accounts payable, accounts
receivable, journal, general ledger, payroll, and trial balance. It functions as an accounting
information system. It may be developed in-house by the organization using it, may be
purchased from a third party, or may be a combination of a third-party application software
package with local modifications. Accounting software may be on-line based, accessed
anywhere at any time with any device which is Internet enabled, or may be desktop based. It
varies greatly in its complexity and cost.
Content management system
A content management system (CMS)  manages the creation and modification of digital
content. These systems typically support multiple users in a collaborative environment,  allowing
to perform document management with different styles of governance and workflows. Usually the
content is a website (or part of it) and the term commonly refers to web content management
systems.  Web content may include text and embedded graphics, photos, video, audio, maps,
and program code (such as for applications) that displays content or interacts with the user. By
their nature, CMSs support the separation of content and presentation.