Internal memory (RAM)

Internal memory (RAM)
Basic organizer functions (appointments, alarms, contact lists, tasks, and memos) don't require much memory. The 32MB amount that comes with the lowest-end current Palm--the $99 Z22--is adequate if these tasks are all you want to do. Third-party software such as utilities and games quickly eat up RAM, however, so look for a model with 64MB or more of RAM--or a model that accepts Secure Digital (SD) memory cards (see below)--if you plan to load lots of extra programs or you want to store lots of media for playback. Newer Palms include ROM for storing the OS and key vital data such as contacts, so that you don't lose them if the battery runs down.

Applications on Windows Mobile devices require more memory, especially to play audio or video. The specs for today's Windows Mobile PDAs usually specify two types of internal memory: RAM and flash-based ROM. The ROM is where the PDA stores the OS and vital data such as contact information. If your batteries run down and your device loses power, the data in ROM is unaffected. RAM, on the other hand, requires power--if you lose power, you lose data in RAM. Most software runs in RAM, so the more you multitask on a Windows Mobile PDA, the more RAM you'll want. Look for a unit with at least 64MB each of ROM and RAM.

Almost all Windows Mobile devices come with external card slots. CompactFlash used to be the dominant expansion format, but SD Card has become more common. Some models accept both CompactFlash and SD Card formats. These slots can also connect to add-ons such as cameras, audio players, phones, or GPS receivers.

from http://tech.msn.com/products/article.aspx?cp-documentid=2746114&page=2