Google is making changes to how its search engine works on mobile devices such as smartphones and tablets, which will affect millions of users. 

The adjustments in the search rankings, which will be released on Tuesday this week, are expected to favor websites that Google has deemed as mobile-friendly.

Websites that are not considered by Google as mobile-friendly will be ranked lower in search results made through mobile devices, while websites considered as mobile-friendly will be shown at the top of the results.

Being at the top of search rankings is a prized position for companies, as this could translate to more customers looking up their business and more profit.

The new search engine formula by Google will not affect searches made on desktops and laptops. However, it is expected to have a major influence on consumer activity, as people are increasingly becoming reliant on using their mobile devices to look up things such as product information and nearby restaurants.

"Some sites are going to be in for a big surprise when they find a drastic change in the amount of people visiting them from mobile devices," said website-building company Duda CEO Itai Sadan. This is why several experts are referring to Google's search ranking changes as "Mobile-geddon."

For websites to be tagged as mobile-friendly, they should be designed to quickly load when accessed through mobile devices. The content should also be easily accessed by scrolling up or down, with no swiping needed to the left or right. Ample-sized website buttons for tapping them on smaller screens also helps.

In comparison, desktop-optimized websites load much slower on mobile devices, with contents that simply do not fit on the screen of a mobile device. Google has long been urging companies to optimize their websites also for mobile devices, as these are where users are searching their information through more.

Google has already revealed these planned changes in its mobile search rankings almost two months ago, in a bid to minimize complaints. Google even created a guide and a tool to allow companies to redesign and check if their websites meet mobile-friendly standards.

The ones that will be most affected by the mobile search ranking change will not be the big companies, which are likely to have already made adjustments to their websites. It will be the millions of small businesses, as they may not yet have the money or need to redesign their websites.

"A lot of small sites haven't really had a reason to be mobile friendly until now, and it's not going to be easy for them to make the changes," said Search Engine Land editor-in-chief Matt McGee.

While the changes may lead to the malpractice of pushing websites to the back of the search results despite being the best one that matches a user's search query, it could be justified as it may be very difficult for a user to access such information on a website that is not mobile-friendly.