Mobile
The word "mobile" has a storied history in the computer world. The term was initially used in the 1980s to describe computers that you could take with you and use while you were on-the-go. These devices eventually became small and light enough to fit on your lap and were known as laptops. For many years, "mobile" differentiated between desktop computers and their portable counterparts.
Then came the smartphone. Spurred by the release of the first iPhone in 2007, mobile phones evolved into small computers that could surf the web, send email, and run different apps. The IT community started using the word "mobile" to describe cell phones as well as computers.
Next came tablets. These lightweight touchscreen devices, which are even more portable than laptops, introduced a new mobile category between laptops and smartphones. "Mobile" evolved into an umbrella term that now describes laptops, tablets, and smartphones.
The Different Meanings of Mobile
When used in different contexts, such as "mobile development," "designing for mobile," and "mobile-friendly," the term "mobile" can have different meanings. For example, "mobile development" typically refers to creating touch-based apps for tablets and smartphones, but not laptops. "Designing for mobile" might refer to responsive web design that supports mobile devices with smaller screens, such as tablets and smartphones.
"Mobile-friendly" refers to websites that are easy to use on smartphones. In this case, "mobile" is used synonymously with "smartphone," but not necessarily tablet. This smartphone-specific definition of mobile has become common in web analytics. For example, Google Analytics separates traffic by device into Desktop, Tablet, and Mobile categories. "Desktop" refers to both desktop and laptop computers, while "Mobile" refers specifically to smartphones.