Oscar ceremony was launched by Academy of Motion Pictures Arts and Sciences (AMPAS), to acknowledge the excellence in Hollywood. Today, Oscar has become one of the most prestigious award ceremonies across the world. The governing body of Academy of Motion Pictures Arts and Sciences (AMPAS), under whose supervision the Academy award ceremony is organized, has laid down certain rules for Oscar nominations. The Academy constitute of members who, through a process of voting, decide the nominees as well as winners of Academy Awards.
According to rule 2 and 3 of the Academy Awards, "to qualify a film must release in the preceding year from midnight at the start of January 1 to midnight at the end of December 31". Rule 2 also states that a film must be of the "feature-length", i.e. with minimum duration of 40 minutes, except for short subject awards. The next primary requirement is that a film must exist on a 35 mm or 70 mm film print or in 24 frame/s or 48 frame/s progressive scan digital cinema format, with native resolution not less than 1280x720.
All the members of the Academy, associated with the different branches of the filmmaking, vote for nominees in the category that coincides with their branch. Only in case of nominations for Best Picture are all the Academy members allowed to vote for deciding nominees. After the first round of voting, the list of the nominees is announced. The winners are determined during the second round of voting, in which all members are allowed to vote in most of the categories, including Best Picture.