A Transliteration System
It takes time to master the Arabic alphabet. To start speaking right away, we use a transliteration system, which represents Arabic sounds using the Latin alphabet. This is a temporary tool to help you learn vocabulary before you've mastered the script.
You should start writing words in Arabic script as soon as you learn all the letters. It's the only way to develop proficiency in reading and writing.
A good transliteration system gives each unique sound its own unique symbol. This is different from English, where one letter can have many sounds (like 's' in sun, prism, and treasure) or one sound can have many spellings (like 'f', 'gh' in laugh, and 'ph' in philosophy).