Concentration meditation involves focusing on a single point. This could entail following the breath, repeating a single word or mantra, staring at a candle flame, listening to a repetitive gong, or counting beads on a mala. Since focusing the mind is challenging, a beginner might meditate for only a few minutes and then work up to longer durations.
In this form of meditation, you simply refocus your awareness on the chosen object of attention each time you notice your mind wandering. Rather than pursuing random thoughts, you simply let them go. Through this process, your ability to concentrate improves.