The Prophet [peace be upon him] stated:

مَنْ قامَ رَمَضانَ، إِيماناً واحْتِساباً ، غُفِرَ له ما تَقدَّم مِنْ ذَنْبِه

Whoever stands for prayer in Ramadan with faith and anticipation, will have his previous sins forgiven.

[al-Bukhārī and Muslim]

Imām Nawawī [d 676H] states:

Standing in Ramaḍān refers to the Tarāwīḥ prayer.  The scholars agree upon the fact that it is a recommended prayer, but differ on whether solitary prayer in one’s house is more virtuous or the congregational form in the masjid.  The majority of scholars, including Imām al-Shāfi‘ī and most of his followers, Abū Ḥanīfah, Aḥmad, some of the Mālikī jurists and others, opine that the congregational prayer is more virtuous as this was practiced by ‘Umar and the rest of the Companions, and remains a practice of the Muslim nation and has become an overt symbol of the religion much like the ‘Eid prayer.  Imām Mālik, Abū Yūsuf the student of Abū Ḥanīfah, some Shāfi‘ī jurists and others hold the view that solitary prayer in one’s house is preferable due to the Prophetic saying:

أَفْضَلُ الصَّلَاةِ صَلَاةُ الْمَرْءِ فِي بَيْته إِلَّا الْمَكْتُوبَة

The best prayer is the prayer of a person in his house, apart from the obligatory prayers.

[al-Bukhārī]