When the solid has a high affinity for water - in which case it is called hydrophilic (high energy e.g. glass)- water spreads. In the opposite case of hydrophobic (low energy e.g. teflon) surfaces, water does not spread but, instead, forms at equilibrium a spherical cap resting on the substrate with a 'contact angle'.
Infections such as trichomoniasis, gonorrhea, and Chlamydia (all STDs); and yeast infection can all cause vaginal discharge. Vaginal discharge can be associated with other symptoms such as burning or itching. Antibiotics are given for infections that cause vaginal discharge.
Your cervix will be soft and open during vaginal discharge and you may be pregnant.  â¦ Although I can't really improve on TrishaR's answer I'll add that a white discharge is also symptomatic of an STD.   It's a definite and inescapable symptom of gonorrhea for males, and sometimes for women.