When referring to the homepage, a trailing slash after the hostname is optional since it leads to the same content ("https://example.com/" is the same as "https://example.com"). For the path and filename, a trailing slash would be seen as a different URL (signaling either a file or a directory), for example, "https://example.com/fish" is not the same as "https://example.com/fish/".
In 1998, two graduate students at Stanford University, Larry Page and Sergey Brin, developed "Backrub", a search engine that relied on a mathematical algorithm to rate the prominence of web pages. The number calculated by the algorithm, PageRank, is a function of the quantity and strength of inbound links.[22] PageRank estimates the likelihood that a given page will be reached by a web user who randomly surfs the web, and follows links from one page to another. In effect, this means that some links are stronger than others, as a higher PageRank page is more likely to be reached by the random web surfer.

WhatsApp was founded by Jan Koum and Brian Acton.WhatsApp joined Facebook in 2014, but continues to operate as a separate app with a laser focus on building a messaging service that works fast and reliably anywhere in the world.WhatsApp started as an alternative to SMS. Whatsapp now supports sending and receiving a variety of media including text, photos, videos, documents, and location, as well as voice calls. Whatsapp messages and calls are secured with end-to-end encryption, meaning that no third party including WhatsApp can read or listen to them. Whatsapp has a customer base of 1 billion people in over 180 countries.[46][47] It is used to send personalised promotional messages to individual customers. It has plenty of advantages over SMS that includes ability to track how Message Broadcast Performs using blue tick option in Whatsapp. It allows sending messages to Do Not Disturb(DND) customers. Whatsapp is also used to send a series of bulk messages to their targeted customers using broadcast option. Companies started using this to a large extent because it is a cost effective promotional option and quick to spread a message. Still, Whatsapp doesn't allow businesses to place ads in their app.[48]
As an Internet marketing strategy, SEO considers how search engines work, the computer programmed algorithms which dictate search engine behavior, what people search for, the actual search terms or keywords typed into search engines, and which search engines are preferred by their targeted audience. SEO is performed because a website will receive more visitors from a search engine the higher the website ranks in the search engine results page (SERP). These visitors can then be converted into customers.[4]