It's a term of endearment often used in romantic songs and poetry, expressing love and affection. It's a very common phrase in Indian culture and is often used in various contexts.
Here are some examples of how it can be used:
* "Sajna re, aao na" (My beloved, come here)
* "Sajna re, main tumse pyar karti hoon" (My dear, I love you)
* "Sajna re, mere dil mein baso" (My beloved, reside in my heart)
The term "sajna" itself is a Hindi word for "beloved" or "lover," and the "re" is a vocative particle that adds emphasis and affection to the address.