A feature phone (dumb phone, regular phone) is a regular mobile phones, in contrast to smartphone. A feature phone is best defined by what it does not have. Feature phones normally do not have a QWERTY keyboard, or Touch screens.
It may be a camera phone and have a digital camera, run Java or C appplications, probably through J2ME or BREW. Feature phones do not typically have access to more advanced applications written in native code, such as Symbian.
If someone is referring to a mobile phone, they are probably referring to a feature phone. Some companies, such as Helio, which exclusively support smart phones, have used unique marketing campaigns.
Feature phones with a particular focus on appearance may be considered a fashion phone, like the popular slim clamshell phone Motorola Razr.
From a microbrowser perspective, smartphones distinguish themselves because they can run advanced mobile web browsers like Opera Mobile, while feature phones, even high end ones like the Sony Ericsson W810, can only run limited versions like Opera Mini. This is mainly because feature phones have less memory and processing power to cope with advanced software.
Feature phones with a particular focus on appearance may be considered a Fashion phone