Customer tags can only be applied to customers.
Membership tags can only be applied to memberships.
Why is this relevant?
The main reason is that these two common tag types are often used with Price Rules -- which give automatic discounts if someone has a special tag assigned to them.
Its common for host's to want to give discounts to customers on memberships. And, to save time, these hosts can tag an entire membership with a membership tag. This then tags all customers on that membership with that membership tag. This is faster than tagging all customers individually with customer tags.
A case for customer tags
Hosts can set up a marketing sequence that auto-adds a tag to any customer that performs a specific behavior. For example, if a customer purchases a membership, tag them automatically with a tag that's associated with a price rule. To learn more about how sequences and their additional functionality click here.
So, unless you are using sequences to auto-tag your customers, then consider saving time when setting up price rules by using a membership tag. You can always remove these tags quickly later on if you decide to give Sequences a try.
Here's how to set up a price rule, using a membership tag.
To learn how sequences work and they can grow your business, click here.