What does e-commerce primarily involve?

E-commerce primarily involves online purchases and financial transactions, which encompass a wide range of activities conducted over the internet. This includes buying and selling products or services via digital platforms, where consumers can browse items, place orders, and make payments electronically. The ease of access to a global marketplace and the ability to complete transactions from anywhere with an internet connection are defining characteristics of e-commerce.

In contrast, the other options represent traditional or alternative sales methods that do not utilize the internet for transactions. In-person sales require the physical presence of both the buyer and seller, telemarketing involves selling through phone calls, and mail-order catalog sales rely on physical catalogs and traditional shipping methods. These methods lack the immediacy and convenience that e-commerce provides, making the correct answer stand out as the most relevant definition of modern commercial practices.