Electronic commerce transactions; EC transactions
“An electronic transaction is the sale or purchase of goods or services, whether between businesses, households, individuals, governments, and other public or private organizations, conducted over computer mediated networks. The goods and services are ordered over those networks, but the payment and the ultimate delivery of the good or service may be conducted on or off-line.” 
A mobile e-Commerce transaction is an e-Commerce transaction that is initiated and performed using a mobile device, such as a mobile phone or a laptop, over a wireless access network or a short-range wireless link.
E-commerce transaction was defined by OECD  from business and statistical perspective. The parties above can be individual customers (C), companies (B), or governments (A). One speaks accordingly about B2C, B2A, B2B, C2C e-Commerce and e-Commerce transactions. Historically, Electronic Data Interchange (EDI) was the first technology used in B2B and B2A e-commerce since 1970's. EDI is based on a number of agreed-upon (EDIFACT) message types whose instances are exchanged by the parties. Notice that B2C, B2A, B2B and C2C e-Commerce are usually governed by different laws. HTTP, HTML, and WWW server and browser technology matured during 1990’s and E-commerce for individual customers (B2C, C2C) became possible. Physical (tangible) goods need to be delivered through a separate logistics channel, whereas digital information (“intangible goods”) can be delivered through the same digital network as the order. Especially the global digital network (“Internet”), simultaneous emergence of suitable digital contents (software, music, videos, maps, etc.), and global payment infrastructure (credit cards, international banking) have made global digital B2C and other e-Commerce to explode since mid 1990's. Perceived as a distributed application one can require that a typical (B2C) e-Commerce transaction, during which a customer buys a good or goods, must satisfy money atomicity, goods atomicity, and certified delivery . A more technical view is that an e-Commerce transaction is in general implemented as a distributed, hierarchical workflow crossing organizational borders. While performed, it must satisfy semantically defined atomicity constraints at each level . Money atomicity and other desired properties follow from the constraints and thus the system implementation must enforce them. The challenges are that the steps must be performed by autonomous organizations, the workflow can last days or weeks (order book from USA to Europe) and that the originating entity (customer’s terminal) cannot directly control the emerging execution or its duration, because it cannot decide or even know the emerging structure of the workflow. Rather, the latter is dynamically decided by the seller and its subcontractors (suppliers). A further challenge is that the customer can later optionally cancel the order and return the received goods to the seller. The time window typically varies from 7 to 30 days depending on the local consumer protection legislation. Conceptually, this possible phase belongs to the E-commerce transaction, but in practice this is taken care of by a distinct exception handling transaction that is often semi-automatically or manually performed.