Some BASIC programmers come from the experience of needing to fit their programs in 4K of RAM or less, so it feels natural to give variable names single letters such as a, b, c or I, j, k. Of course most classic BASIC interpreters don't have support more for than 2 characters for variables. Some BASICs will let you call your variable 'count' but only the c and o will be recognized as the variable name.
In programming languages today including Liberty BASIC, you can give your variable names and other things such as subroutines and functions longer names. What's more, computers have so much memory that we can dispense with trying to save memory with short variable names. And if you're used to using line numbers I strongly encourage you to discard them in favor of named labels. Once you are used to this it will make your programming better.
Why does it matter?
Programming is an exercise in thinking and so it is really important to pick the best possible names for the parts of your programming ideas. When you or somebody else reads your code it will help to understand the code if the variables and function/sub names are chosen well.
What if you are about to go to the store to buy some milk and you told your friend "I'm g to the s to b some m." How well would you be understood?
So, when you write code ask yourself (or the coder next to you) what is the best name for this variable or routine? Later on you may even realize there is a better name and so don't hesitate to act on that impulse and update your code with the new better name.
Think of your coding as a journey to discover the truth of the code, and naming things is an important part of the discovery.