The season of Lent, the weeks where Christians fast and give up worldly pleasures ahead of Easter, begins on Valentine's Day.

It's a time for Christians to pray, reflect, fast and give to the poor. It's also why the McDonald's Filet-O-Fish will be so popular over the coming weeks.

Here's what you need to know about Lent:

What is Lent?

Lent represents the 40 days Jesus wandered the desert praying and fasting after he was baptized, said Fr. Michael Fuller, executive director of secretariat of doctrine and canonical affairs for the U.S. Conference of Catholic Bishops.

Fuller describes Lent as a "time of kind of rejuvenation and refocusing your life on your relationship with the Lord."

How long is it?

Despite Jesus' 40 days in the desert, Lent lasts 46 days. But Sundays during Lent are not "prescribed days" of fasting and abstinence. If you don't count the Sundays, you're left with 40 days of Lenten fasting.

When is Lent? When does it end?

Lent begins on Feb. 14 and ends on Holy Thursday, which is March 29, when there is a mass to represent Jesus' last supper.

On Good Friday, (March 30) Jesus was crucified and on Easter (April 1) he rose from the dead.

Why fasting and what are the rules?

Fasting, abstinence and giving up attachments are forms of self-denial, which trains the soul to desire things less and desire God more, notes Fuller.

The Conference of Catholic Bishops said people ages 18 to 59 should fast on Ash Wednesday and Good Friday. That means followers should have one meatless meal, plus two small meals on those days. No other food should be eaten between meals, but all liquids are on the table.

On Fridays during Lent, Catholics 14 and older are instructed not to eat meat, meaning anything from chicken, cows, sheep, pigs or birds is prohibited. Fish is allowed to be eaten.

More on Lent: 13News Now's Fish Fry Finder

Why the ashes on Ash Wednesday?

The ashes represent two Biblical themes.

The first comes from the saying "remember you are dust and to dust you shall return," a passage underscoring life is temporary and should be lived correctly, Fuller said.

The ashes also pay homage to penance. When someone repented their sins, it used to be custom for them to dress in itchy sackcloth (like a potato bag, Fuller says) and sit in ashes.

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