To secure a domain name for a website, you must first purchase the domain separately from web hosting. The domain name will function as the address where people access the site. You then need to purchase web hosting to store the website files on servers. It's recommended to purchase the domain name immediately even before designing the site to prevent others from taking it. Consider variations of the business or brand name with different domain extensions like .com, .net, or .biz if the top choice is unavailable. Also purchase additional related domain names that could attract visitors and forward them to the main site.