The web is built on links, and web users routinely use links to find the information they need. When a site links to your site, web users follow those links, resulting in web traffic, or referral traffic. When these backlinks, also called inbound links, come from high quality sites, they also tell Google your content is authoritative and trustworthy. This is important because inbound links from respected sites are an SEO ranking factor, so they can boost organic traffic, too.
Web analytics is the measurement of the behavior of visitors to a website. In a commercial context, it especially refers to the measurement of which aspects of the website work towards the business objectives of Internet marketing initiatives; for example, which landing pages encourage people to make a purchase. Notable vendors of web analytics software and services include Google Analytics, IBM Digital Analytics (formerly Coremetrics) and Adobe Omniture.