What is seva main in informal Hindi letter writing?

Seva ka matlab hai doosron ki madad karna ya unke liye kuch achha karna. Ye ek tarah ka samarpan hai jismein hum bina kisi swarth ke, apne samay aur shakti se doosron ki seva karte hain. Chhoti-chhoti cheezein, jaise kisi ki madad karna ya unka haal chaal poochhna bhi seva kehlata hai. Iska maqsad samaj mein sukh aur shanti phailana hota hai.