Global picklist set in Salesforce

A Custom picklist is a list tied to a particular object as a field on the object.

A Global picklist is which exists independently as a global value set. Its values are shared with any object picklist based on it.

Steps to add Global Picklist Value Set in Salesforce :

1. Search for Picklist in the Quick Find box, then select Picklist Value Sets.
   
2. Add Global Value Sets by clicking a new button, In the below screenshot Global set is created for the country field.
   
3. We can select the options to sort the values alphabetically or to use the first value in the list as the default value or both.
   

   Then, click Save.
   The global set value for a country is created. we can use them for multiple fields without adding the values every time
   While creating the new custom field of type picklist we can select the global value set as shown below.