how can bind any string of text, so whenever you type it, it will be replaced into another string I tried my best to describe it, I saw this functionality in some video about macos for noobs.

Basically you can bind any string of text, so whenever you type it, it will be replaced into another string. It seemed super easy. 

Example, you bind 

&lt;something&gt;


to xsy
So whenever you write xsy, it gets replaced by 

&lt;something&gt;


etc
Go to System Preferences > Keyboard > Text and add your text for Replace and With by clicking the + in the lower left of the window.

Once added, you can edit an entry by selecting the row and then click the field to open the edit window.

To remove a row, select it and then click the - in the lower left of the window.