Reality has many intersections.
Tweeting while watching TV is an example of two channels working together to support a single context.
A single channel can also support multiple contexts.
For example, a website may serve someone browsing on a phone from their couch, on a tablet at a coffee shop, or on a desktop computer in a cubicle.
When you begin to unravel a mess, it's easy to be overwhelmed by the amount of things that need to come together to support even the simplest of contexts gracefully on a single channel.
"It's just a ____________" is an easy trap to fall into. But to make sense of real-world problems, you need to understand how users, channels, and context relate to each other.
What channels do your users prefer? What context are they likely in when encountering what you're making? How are they feeling? Are they in a hurry? Are they on slow Wi-Fi? Are they there for entertainment or to accomplish a task?
Considering these small details will make a huge difference for you and your users.