Ajami script is a way of writing some African languages using the Arabic alphabet. Imagine that you have a special code for writing down the sounds in English. So instead of writing the letters A, B, and C, you would write different symbols for the sounds "ah", "buh", and "cuh". The Ajami script is like that, but for African languages.
People in Africa have been speaking diverse languages for a long, long time. Some of these languages have their own unique writing systems, while others don't. In areas where Arabic was introduced, people started adopting the Arabic alphabet to write down their own languages. But since Arabic was designed for a different set of sounds, they needed to tweak the alphabet a little bit to fit their needs. They added some new letters and changed the shapes of others.
For example, in the original Arabic alphabet, there is no letter for the "sh" or "ch" sound. But some African languages have this sound, so they added a new letter to represent it. In the Ajami script, there are also special symbols for consonants that don't exist in Arabic, like the "gb" or "kp" sounds.
Using the Ajami script has helped people in Africa preserve their languages and share them with others. It's like having a secret code that only people who know your language can understand!