For the first few years, Google was primarily a search engine with hardly any extra features.
Tabs were introduced in 2001 for easy access to more focused searches.
Tabs not only graced the search page, but they also appeared in projects like Gmail and Calendar.
Those trusty tabs become links that rest atop the Google search page.
The navigation bar was nixed in favor of a nested application menu with Google+ info tacked on for good measure.