「今日」 means today, referring to the current day. It is a very common word used daily to talk about events or plans for the present day. You will use it frequently in conversation.

現在(げんざい)の「今日(きょう)」を意味(いみ)します。毎日(まいにち)の会話(かいわ)や、その日(ひ)の予定(よてい)について話(はな)すときに使(つか)います。