Each piece of software works with a character set. A character set is a set of symbols, including letters, digits, spaces, and other symbols. A character set is a collection of encodings and symbols. A character set's character comparisons can be done using a set of rules called a collation.
For example, let's say we take the letters from a to z from the alphabet. Each letter gets a number in order; a = 0, b = 1, c = 2, etc… The letter a is the Symbol and the number 0 is the encoding for the letter A. The combination of letters and encodings form a character set.
Firebase and InterBase both support more than 20 different character sets for use around the world. When building a database, if you don't specify a character, the IBExpert program will automatically use the default character set it automatically assumes. The chosen character set is very important when importing and exporting data with different character sets. This needs to be taken into consideration when applications are developed with multiple language versions.
It is crucial to specify the appropriate default character set for your application and requirements.
Generally this default character set cannot be altered at a later date (only using the command line tool IBEScript). Alternate character sets can however be defined for individual domains and tables, which override the default character set.