Qual é a diferença entre omnibar ou (omnibox) e a barra de endereço?
O omnibar (também conhecido como omnibox) é a barra de endereço combinada com a caixa de pesquisa do google.
As browsers evolved over the years developers began to combine the address bar and the search field. The first major browser to do this was Google Chrome.
The bar at the top of Chrome is called the omnibar. Basically, the omnibar combines your regular address bar and the Google search box into one area in your browser.
The omnibar records your search history just like the search field on google.com and offers search suggestions based on worldwide aggregate data. It also shows you suggestions of web sites you have visited before as you start to type.
Fonte A diferença entre a barra de endereços e o campo de pesquisa do Google
Most modern browsers are equipped with a toolbar, featuring both a URL and a search field. While straightforward, this UI configuration can lead to some confusion and a general feeling of unnecessary complexity. The purpose of Chromium's omnibox is to merge both location and search fields while offering the user some highly relevant suggestions and / or early results.