To establish an online presence, one needs an email address, domain name, and web hosting or website builder. An email address is required to register a domain name, and popular free providers include Yahoo, Gmail, and Hotmail. Domain names identify websites and it's wise for businesses to register their company name's .com version if available. Web hosting provides storage and accessibility for websites, with shared hosting being the most affordable option. Website builders allow anyone to easily create professional-looking sites without HTML knowledge.