集中 (shūchū) means “focus” | MotiTan Japanese Dictionary

More examples

静かな部屋では集中できます。shizu ka na heya de wa shū chū de ki ma su

You can focus in a quiet room.

It describes directing mental attention toward one thing instead of letting it spread across many things.

注意chūi: The mental act of paying attention to a particular person or thing.

ある物事に意識や注意を一つに向けること。a ru mono goto ni i shiki ya chū i o hito tsu ni mu ke ru ko to

集中 (shūchū) is a Sino-Japanese compound of 集 (shū, "gather") and 中 (chū, "center"), expressing attention gathered toward one point.

In everyday conversation, 集中する (shūchū suru, "to focus") presents focusing as an action, while 集中している (shūchū shite iru, "be focusing") describes the ongoing state.