A Global List is an account-wide list that can be used in any form. A Global List is a legacy feature and is the predecessor to the Lookup List. Global Lists are predefined into four columns: Name, Value, FilterKey, Score.
1) What is the Name in a list?
The name is what is shown/displayed in the apps. This does not have to be the same as the value, although it is set this way by default.
2) What is the Value?
The "value" is what is shown on the reports. They would not be the same in many instances, most often used with calculations to automatically calculate different fields in your form.
3) What is the Filter Key?
The "filter key" is used to filter your list based on another list
4) What is the Score?
This is also used in calculations. You can assign a numerical score to a list selection. For example, if you have a product price list, you can assign numeric values to your products, pull those into a calculation field to use for calculations, etc.
Note: your created list can only be in .csv or .xlsx formats.