Your question is unclear. The computer world has more than 2 things—
while bit states can be only 2; 0, and 1.
The concept of images and containers is the same as class and objects. You write the class in your Java file, and when that code runs, the classes (when instantiated) become objects. The separation is to make it clear that while the class code is shared, each class instance (the object) can have its state and perform its operations. Similarly, each image specifies the code it executes and the resources it consumes. But, each container that is running can receive requests from different clients and provide a response back to them.
Quote:
Wouldn't it be right to run it only with images
You're right. You run the Docker-based apps with images. But how would you distinguish between images and "running images"?
The running images are the containers. Each container exposes various details and properties that are not available with an image;
such as a terminal that can be used to execute certain commands.