A TracFone is a type of "prepaid" cell phone. Instead of paying one specified amount of money per month for service, you do not enter into a service contract and instead pay in advance for all the cell minutes you plan on using. The "firmware" is the software that operates your TracFone, and updating this firmware can improve the performance of your device and even add new features.
Look for an "Update" function within the menu of the phone itself. Whether or not your TracFone has an "Update" function will depend on exactly which model phone you own. If your phone has this function, it will typically be in a "Settings" or "Applications" sub-menu within the main menu that is on screen when you boot up your device.
Find your "update number." TracFones on certain networks need to dial a telephone number to receive software and firmware updates on their phone. The phone then uses its active data connection to download and automatically install these updates. Some providers only have one update number across all phone models. Other phone service providers, like Verizon or AT&T, have different codes that you can dial. This specific number will be listed in the manual that came with your TracFone.
Dial your update number. For example, Alltel network TracFone customers can dial "*228" (without quotes) just like you would dial a regular phone number and automatically receive any available updates.