(Khalwa). The spiritual retreat and seclusion. Initially seclusion is undertaken by physically withdrawing from those outside disturbances which have the potential of distracting one in his contemplation of Allah's Names and Attributes. Ultimately this withdrawal becomes purely spiritual when the heart is in a state of perpetual presence with Allah . Then the lover of Allah is with his Beloved at all times, regardless of the external conditions within which he is situated. Seclusion is the conversation of one's secret awareness with Allah. This is known as 'Khalwa fi Jalwa' (Seclusion within society) - as you are in a private state of seclusion with Allah while going about your everyday activities.
(Jalwa). The knower ('Arif) is the one who observes the spiritual retreat (Khalwa) while being engaged in everyday activities within society (Jalwa). During such a time, when he is present with Allah, he finds inexpressible sweetness (Halawa). Such a lover of Allah is also called 'one who is engaged and yet is free' or 'busy/not busy'.
(Halawa). When Allah opens the doors of His Loving-Kindness to the heart of His lover that heart becomes infused with joy and is overwhelmed by inexpressible sweetness. This is the opening of sweetness (Futuh al Halawa).