The five (daily) prayers and one Friday prayer to (the next) Friday prayer are expiations (for the sins committed in the intervals) between them.
عَنِ النَّبِيِّ ﷺ قَالَ الصَّلَوَاتُ الْخَمْسُ وَالْجُمُعَةُ إِلَى الْجُمُعَةِ كَفَّارَاتٌ لِمَا بَيْنَهُنَّ