Jewish Festivals are listed in the Torah and are of two types: 

1. Three pilgrimage festivals (shalosh regalim):

• Passover,
• Shavuot, and
• Sukkot (including Shimini Atzeret).

These festivals were celebrated in ancient times by "appearing before God"--by bringing offerings to the Tabernacle or Temple.

2. High Holidays: 

• The Jewish New Year (Rosh Hashana—“Yom Teru'a” in the Torah), and the
• Day of Atonement (Yom Kippur).

 
Duration
Jewish holidays that were originally one day are now observed as follows:

• Rosh Hashana--2 days.
• Yom Kippur--1 day.
• Shavuot--1 day in Eretz Yisrael or 2 days elsewhere.
• Passover has festival days at the beginning and end of the holiday and intermediary days of lesser holiness, which are called chol ha'moed. In Eretz Yisrael, Passover lasts for 7 days in total and the first and last days are festival days. Outside of Eretz Yisrael, Passover lasts 8 days and has two festival days at the beginning and two at the end.
• Sukkot has festival days at the beginning and at the end and intermediary days of lesser holiness, which are called chol ha'moed. In Eretz Yisrael, Sukkot lasts for 8 days and the first and last days are festival days (the last day is Shimini Atzeret). Outside of Eretz Yisrael, Sukkot lasts for 9 days and the first two days and last days are festival days (the 8th day is Shimini Atzeret and the 9th day is Simchat Torah).

Character
Each holiday contributes its own character to Jewish life (Passover--the theme of freedom; Yom Kippur brings atonement, etc.). 

Celebrating
How to celebrate these holidays is detailed in our Oral Law and halacha books. Jewish festivals as practiced today are similar in holiness to Shabbat. As with Shabbat, the Jewish festival has candle lighting, kiddush at two meals, and havdala.   We eat our best food and wear our best clothing on Jewish festivals (we eat our next-best food and wear our next-best clothing on Shabbat!).
The main idea behind eating meals on Jewish festivals is joy (simcha), so you should drink wine and eat meat (only if you enjoy wine and meat).  There is no third meal on Jewish festivals since people used to eat two meals each day (adding a third meal on Shabbat was for enjoyment/oneg).
 
Melachot
Any activities or actions permitted on Shabbat are also permitted on the Jewish festivals. Actions that are forbidden on Shabbat are generally also forbidden on Jewish festivals, but there are some leniencies (only if the actions are needed for that festival day).
Examples

• Lighting from an existing flame,
• Cooking and baking for the Jewish festival day, and
• Carrying outside the eruv (hotza'a--transferring objects between domains).

 
Grama
Grama (indirectly causing an action) is permitted on Jewish festivals (but not on Shabbat). For example, you may advance or delay a timer that will make a light go on or off in the future (the timer must already be plugged in and operating from before sunset of the festival day).
Note For an action to be considered indirect based on time, there must be at least 2.5 seconds after the first action is done before the resulting action begins to happen.

Psik Reisha Dla Neicha Lei
Psik reisha dla neicha lei is forbidden on Jewish festivals, just as it is on Shabbat.

D'oraita Restrictions
D'oraita restrictions apply world-wide to:

• First and seventh days of Passover,
• First and eighth days of Sukkot,
• First day of Shavuot,
• Yom Kippur,
• First day of Rosh Hashana.

Note The same restrictions apply to all other Jewish festival days but are rabbinical.
 
Women
In general, women are not required to perform the positive, time-dependent commandments. Women and girls are not required to eat any Jewish festival meals except the Passover seder meal (but they are not allowed to fast on those days).

Shabbat was the goal of Creation. Just as God completed the world's creation on the sixth day and ceased His work on the seventh, so Jews are supposed to imitate God and not do any creative work on the seventh day. Everything we need for living through Shabbat must be prepared ahead so that we do not do any creative activities on Shabbat.
Our observance of Shabbat thus testifies that God created the world. In the Shabbat kiddush, we mention the Exodus from Egypt, too, to testify to the world that God is continuously involved in our lives.
By ceasing our normal efforts to dominate the physical world, we can appreciate the spiritual aspects of our existence.
On Shabbat, all observant (shomer Shabbat) Jews receive an extra “soul.”

Zachor and Shamor

Remember (Zachor) the Sabbath day to make it holy—Exodus/Shmot 20:8
Observe (Shamor) the Sabbath day to make it holy—Deuteronomy/Devarim 5:12
Shabbat has two dimensions:

• Zachor  “Remember,” encompassing positive (“to do”) commandments, and
• Shamor  “Observe,” encompassing negative (“refrain from”) commandments.

Zachor:  Positive Shabbat Commandments
What Are Positive Shabbat Commandments
Positive Shabbat commandments include:

• Lighting candles,
• Making kiddush evening and morning,
• Making havdala,
• Honoring Shabbat (Kivod Shabbat), and
• Enjoying Shabbat (Oneg Shabbat), including eating three meals on Shabbat.

Honoring Shabbat: Special Food and Clothes
Honoring Shabbat includes eating tasty food and wearing nice clothes.

Shamor: Negative Shabbat Commandments
Shabbat Laws from the Torah (Shabbat D'Oraita)
What Are Melachot
On the Jewish day of rest, we refrain from 39 creative activities (melachot) that had been used to build the Tabernacle in the wilderness. These 39 melachot, prohibited by the Torah, are listed in the mishna of Shabbat and in later halacha books.

The word melacha is frequently mistranslated as “work,” but work has nothing to do with the Jewish concept of melacha. Some melachot are physically strenuous (plowing, grinding wheat, skinning an animal) and some are easy to do (drawing, baking). The defining point is whether the activity is one of the 39 creative, value-adding labors. Emptying your pockets before leaving an eruv (so you are not “carrying”) may seem confusing to someone who thinks that resting on Shabbat means refraining only from hard physical labor!

What Are Toldot
Toldot are variations of the 39 melachot. These types of melacha are also prohibited by the Torah.

Intention and Other Considerations
Most Torah (d'oraita) prohibitions of melacha on Shabbat are for cases in which you:
            1) Intend a permanent change.
                Often, actions that may be forbidden when they cause permanent change, will
                be permissible by Torah law if the result is only temporary. Or
            2) Intend or act for a specific purpose.
                Random or unintended actions are generally not prohibited by Torah law.
                (However, actions that are not prohibited by the Torah, may be prohibited
                by Chazal.)

Whether you may benefit from a melacha done on Shabbat depends on intention:

• A Jew who intentionally does a melacha on Shabbat may never benefit from that melacha.

            Note Any other Jew may benefit from that melacha as soon as Shabbat is over.

• A Jew who does melacha on Shabbat by mistake (shogeg) may benefit from that melacha immediately after Shabbat ends.

In order to violate a prohibited melacha d'oraita, the melacha must be done as follows. If any of these do not apply, then the melacha is forbidden d'rabanan but not d'oraita:

• K'darko--The action must be done in a normal way.
• Tzorech tikun—The action must be done for a constructive purpose.
• Tzricha l'gufa--You must need the normal result of that action.
• Asiya b'yachid—The action must be done by one individual (if commonly done by just one person).
• Mit'aseik--You must realize that you are doing a melacha.

 
Shabbat Laws from Chazal (Shabbat D'Rabanan)
Chazal instituted additional restrictions, such as:

• Activities that might lead directly to violating a Torah prohibition.
• Use of items not designated for Shabbat use (muktza). For a good explanation of muktza from the TorahTots website, please click here.
• Activities that might lead one to think that a prohibited activity is permissible (mar'it ayin--the appearance of the eye).
• Activities that are not appropriate for Shabbat, even though they are technically permissible according to the Torah (“uvda d'chol”).
• Tircha--Exerting a physical effort to accomplish a result that is not required for Shabbat.

Enjoying Shabbat/Oneg Shabbat
Chazal instituted laws to engender a positive Shabbat atmosphere and experience.  Beyond the actual halachot of shamor and zachor, we have a concept of enjoying Shabbat (oneg Shabbat)—of enhancing our experience of Shabbat by doing whatever each person finds to be enjoyable and relaxing--as long as it is neither destructive nor violates the laws of Shabbat. The criteria are subjective. To fulfill the idea of honoring Shabbat, do things you would not do just for yourself if it were not Shabbat. Take essential life activities such as eating and sleeping and do them more and better and make them especially enjoyable.

Meals as Oneg
On Shabbat, we eat better foods and more types of food than we would normally do on weekdays.
The main idea behind meals for Shabbat is enjoyment (oneg; by contrast, the main idea for Jewish festivals is joy--simcha), so on Shabbat you should eat bread and either fish, poultry, or meat (but only if you enjoy them).
In order to have a special appetite for our Shabbat evening meal, we don't eat a full meal with bread on Friday afternoon.

Special Shabbat Songs (Zmirot)
Special songs (zmirot) are sung at the various Shabbat meals. Some zmirot have an aspect of prayer to them.

Studying Torah
Studying Torah on Shabbat is another way of increasing our spiritual experience. It honors the Shabbat and should bring about enjoyment of Shabbat.

Shabbat and Muktza
For information on Shabbat and muktza, see section below, Shabbat: Muktza.

Weekday Talk
Don't talk about subjects that are forbidden to do on Shabbat (weekday subjects); for example, don't talk about what you will do after Shabbat is over. There is no prohibition about discussing actions from the past as long as no planning is discussed.

After saying the main blessing of tefilat ha'derech, some people have the custom to say these phrases (psukim) three times each:

• L'shuatcha kiviti...
• V'ya'akov halach l'darko...
• Yivarechecha...
• Hinei anochi sholei'ach lifanecha...