What is the difference between an API and SOA

There are a lot of What is the difference between... questions out there but I couldn't find this one.

Wikipedia says this about an API
An application programming interface (API) is a source code-based specification intended to be used as an interface by software components to communicate with each other. 

And this about SOA

SOA also generally provides a way for consumers of services, such as web-based applications, to be aware of available SOA-based services. 
Aren't both technologies where you present services to other services?
Could someone expand on this?

Aren't both technologies where you present services to other services?
Could someone expand on this?

Thank you