Coinciding with the month of Ramadan, of course, all Muslims multiply their worship which is usually done at the mosque. I'tikaf is one of the practices of the Sunna in the holy month of Ramadan, which certainly can make Muslims closer to Allah SWT.
I'tikaf itself means stopping or staying in the mosque with the sole intention of worshiping Allah SWT. All Muslims do I'tikaf can at any time and the law is sunnah for all Muslims. I'tikaf should be done in the mosque and more importantly in the last ten days of Ramadan, as did the Prophet Muhammad.