This Global picklist is available in all the edition from Spring 16 release. I hope most of them aware of it if not here you go.
What is Global picklist?
You can say Gobal picklist as 'Universal picklist values' because you will create a picklist values in one place(Global picklist) and you can use those values while creating custom picklist field in different objects.
Creating Global picklist:
Lets take an example, I have objects called Student application & Student in these two object I have to create a picklist field called Education and the values of this fields are 1. Bachelor degree 2. Master degree 3. Ph.d etc.
Before this global picklist functionality, we will create this Education picklist field in this two objects by entering the values. Suppose if I have to modify or remove any values then I have to do it in both the fields in this case in two different object and that fields.
So, it will be a headache in large application because if you miss in any place then your application will be mess, but now you know need to worry about this because we have Global picklist. You can create a single picklist values and you can use those values in any picklist fields in any objects in that salesforce organization.
To create Global picklist Go to Setup--> Create --> Picklists and click 'New' to create a Global picklist and enter 'Label' for your global picklist as shown in below image and optionally you can enter the description and click save.
Now the page you are looking is the Global picklist detail page click 'New' on 'Picklist Value Set' to enter the picklist values for 'Education' global picklist. You enter the value as shown in the below image.
You are done with creating the global picklist. You global picklist detail page will look like below screen.
Using Global picklist in custom picklist field:
Now we are going to use this global picklist in our two objects custom picklist called 'Eduction' Here I going to demonstrate for only one object for another object you can follow the same steps.
First create a custom object called Student and click 'New' to create a custom field and we have to create picklist so, we will select the data type for my custom 'Education' as picklist and click next and you will get the below screen.
In the field label enter value as 'Education' . In the 'value' property we have 2 option those are
1.Use global picklist definition
2.Enter values for picklist, with each values separated by new line.
We are going to use global picklist so don't change the option and in drop down you can see 'Education' global picklist which we have created select that 'Education' and click next and save the field.
Now you if you go and create a Student record you can see the 'Education' picklist field in that you can see the values which we have entered in the global picklist.