Android

An android is a totally synthetic machine, built as the analog for a human being. Unlike cyborgs, androids are not constructed from any organic parts.

How androids work

At the time this article was written (The Present), mankind is not even close to having the capability to build androids, but they were able to make the next best thing........real dolls. Fortunately for Science Encyclopedia, smarmy people from The Future elected to travel back in time, and brag about how nice theirs are - plus have a laugh at our primitive real dolls.

Androids work (future not-happened-yet-tense) by implementing as many traits that make them seem as legitimately human as possible. This means physical characteristics indistinguishable from the real thing - such as skin, hair, warmth, respiration, and a pulse (and genitals). The awesome advanced technology of the future allows for the manufacture of synthetic skin and muscles that are totally life-like. These androids also have hair and nails that "grow" by themselves.
Unlike humans, androids have been designed to exist indefinitely (only requiring the occasional replacement of its plazmatron matrix.....um....what you primates would call batteries). This is due to the fact that there was a sharp decline in the sale of Nexus series replicants once customers found out about the planned obsolescence.

The hardest part to nail down was artificial intelligence. The problem with it was the fact that true sentience leads to free will. This is not at all what the consumer wants since many of them are looking for "fully functioning human analogs that don't exactly say no -wink wink". The solution to this problem was to write billions of "If/Then/Else" statements to cover any conceivable circumstance the android would ever encounter.
After much trial and error, an acceptable consumer friendly version of artificial intelligence was developed. Likewise, the term "free will" is now advertised as "unlimited will" (modeled after Verizon's wireless internet service).

What androids are used for

Originally, androids were used for various forms of labor. The problem with this is the the fact that these androids put all the consumers out of work. This made the money that was saved on cheaply producing their products moot since 95% of the population couldn't make money to buy anything.
It was later decided to give humans their jobs back - excluding exceedingly menial tasks such as fast food, landscaping, phone based customer service, or factory work. To keep from being totally marginalized, the companies that manufactured androids soon found a profitable market for erotic products. Needless to say, Suck-A-Tron® Incorporated and Custom Slut® Global are......er.......will be household names.