The word Vrata means vow. There are many Vratas and festivals told in our scriptures. Some are observed everywhere like Shiavaratri and some are observed more in specific geographies.
In general during the Vratas the Upavasa is observed. The word Upavasa refers to "living close to (God)". In essence the observer lives in the spiritual connect with the God during those day/days. To accomplish that extravagant desires on food /sleep etc are avoided.
Each of these vratas gets us specific benefits told in the scriptures. All of them for sure gets us the Grace of Lord Shiva.
Let us all make effort to observe all those Vratas and Festivals to the extent possible.