This is an interesting issue. Simplified and Traditional are different (but closely related) writing systems that can be used to express the exact same text. They are not different linguistic variants of Chinese. It looks like regardless of which writing system you choose, Google still translates into the most widely used variant of Chinese: Standard Chinese, as spoken on the mainland. It just writes the result using…
To clarify, "Standard Chinese" is the English term to describe the official language of the PRC. There is no country called "mainland," nor is there a country called "mainland China," nor is there a language that can be accurately called "Chinese." It's much more clear in Mandarin itself, such as 官話. Note that some might translate this as "Traditional Chinese," separate from the typical meaning, when trying to separa…
"Standard Chinese," "Mandarin Chinese," or however you want to call it (there are several terms in Chinese itself that refer to essentially the same thing) is the official language both on the mainland and in Taiwan. They have slightly different variants, but both standards grew out of the same historical movement to standardize Chinese. Both the Republic of China and the People's Republic of China wanted to create a national standard to enable universal communication in the country, and the PRC essentially adopted the standard the ROC had been working on.