Data transfer modes that are based on packet switching method rather than circuit switching, and offer a much faster and more efficient data transfer. For more information and comparision see for example here.

Multimedia Messaging Service (MMS) is a standard for telephone messaging systems that allows sending messages that include multimedia objects (images, audio, video, rich text) and not just text as in Short Message Service (SMS).

RAM (Random access memory ) is the internal memory of the phone used to execute programs etc.

Display technology in use. The options (from worse to best) are STN (LCD), CSTN (Color STN), TFT (Thin-Film Transistor), and OLED (organic light-emitting diode). The first three are all based on LCD technology, which unlike OLED, do require backlight.

Built-in storage memory expresses the amount of memory space available for storage of ringtones, pictures, videos, games etc. The most commonly used memory type is flash.