My sudden urge to know about Zen made me wander through a few blogs. Here is what I have understood:

Zen means waking up to the present moment. That is, perceiving this moment exactly as it is, rather than through the filter of our ideas, opinions, etc. One way to practice this is to ask yourself a Big Question, such as “What am I?” If you ask such a question strongly and sincerely, what appears is “Don’t Know.” This don’t-know is before thinking. If you keep it moment to moment, then everything is clear. Then, each moment, whatever you’re doing, just do it. When you’re sitting, just sit; when you’re eating, just eat; and so on. According to Zen, existence is found in the silence of the mind (no-mind), beyond the chatter of our internal dialog. Existence, from the Zen perspective is something that is only happening spontaneously, and it is not just our thoughts. All of life that we perceive is constantly in a state of change. Every atom in the universe is somewhere different every millionth of a second.

Zen says that if we entertain no personal version of what we think existence is, in other words, if we hold no subjective interpretation of what existence is, at the moment we are free of any notion at all, we will experience existence instantaneously, spontaneously.