Email delivery determines whether or not the email you send is accepted by ISP. In other words, email delivery only gauges the emails which are not bounced, regardless of if the email reached the recipient's inbox folder or not. It is also called "acceptance rate".
“Email delivery” and “email deliverability” are two different metrics even though they sound very similar. You may think the correlation between them as two steps in the same process;
Step 1: Email Delivery Is the email accepted by ISPs?
Step 2: Email Deliverability Is the email reached to the targeted inbox?