I saw questions touching this subject in the archives, but it is still not very clear to me. Is it a must for a woman to wear socks? Where does it say so? In case of a long skirt, is it still a must? Can my toes be seen in sandals?

Shalom U'varacha The Gemara (Berachot 24a) states that the "Shok" is a place that needs to be covered. The Poskim differed in their definition of the word "shok". There are those who define this as the lower part of the leg (Shulchan Aruch HaRav, Aruch HaShulchan, Chazon Ish) and therefore a woman needs to wear socks and cover her lower leg. Other opinions hold that the "shok" is the upper leg (Mishnah Berurah, Pri Megadim) in which case she needs to cover below the knee but socks do not have be worn. In addition there are laws that can be defined as the regular custom in each place. If the custom is to wear socks it could be argued that a woman who does not wear socks is breaking what is called "Dat Yehudit". There are opinions that even according to the more strict opinion a woman who wears a long skirt does not need to wear socks. I heard this from several poskim, such as Rav Mordechai Eliyahu. Kol Tuv