How to focus on one thing like a monk? Question : How to focus on one thing like a monk ( ideal one )?

Is there a well defined meaning of word " focus " in buddhism? I want to learn the technique through which I can focus on one thing at a time like a monk.
In Buddhism it is recognized that mind is not static, it's not like a lense that can be focused. Mind is something that unfolds, moment after moment. If you sit down and watch your mind unfold for a while (an exercise called meditation) you can notice that the state of mind flows from current to next through its associations in memory (plus distractions from the senses).

One simple way to achieve concentration (after calming down and reducing inner and outer distractions) is to condition this associating process to come back with questions and thoughts about the same "thing", instead of it coming back with other related topics. Basically, you can keep asking yourself questions about the object, and for each question instead of answering from memory you should come back to the object and reexamine it. 

This is not really a one pointed concentration yet though, just regular meditation on a given topic. To achieve real one pointed concentration you need to shift attention from object itself to the image of object in your mind. If you look very carefully, you can see that the image of the object in your mind is never complete, it only has one-two elements or attributes of the object at any given time, not all at once. In fact, if you pay attention you can see how your mind is hard at work assembling the experience of the object from its multiple attributes by cycling through them.

If at this moment, when seeing this cyclic assembly process, you shift your attention from the image of the object to mind itself, while letting it continue doing its assembly thing, you will have achieved one-pointed concentration.