The Wayback Machine is an online service that takes screenshots of sites, allowing users to see what a site looked like at different times (what changes have been made over the years of its existence).

Most sites make frequent changes. The Wayback Machine allows you to view content that no longer exists on a site. The service can also be used for troubleshooting.
However, some sites may not appear because they are password (or for some other reason).
Go to the official Internet Archive website and enter the URL of the site you want to view in the Wayback Machine address bar. After typing the URL, click on “Search History.”
Next, you will see a timeline with all the years for which a screenshot of the site you are looking for exists.
Select the year you want to view.
A calendar of the selected year will appear. Some dates in that year are colored in a specific color. What does this mean:
- No color: There is no screenshot for this date.
- Blue color: There is a screenshot for this date.
- Green color: Redirect (3xx).
Also, some circles on the calendar are larger than others. This means that the site has many screenshots for that particular date (this does not represent the number of times the site has been updated).
Select the date/time you want, placing the mouse cursor on the date and select the screenshot from the pop up menu that appears.
Now, you are able to browse the archived version of the site.
However, there are other solutions available for browsing older versions of sites, such as oldweb.today, but the Wayback Machine contains the largest archive of all digital libraries available on the internet.

This was the browsing process for older versions of a site, as we read it on Howtogeek.
