Chol HaMoed, a Hebrew phrase meaning “weekdays of the festival”, refers to the intermediate days of Passover and Sukkot. As the name implies, these days mix features of “chol” (weekday or secular) and “moed” (festival).
Purim (meaning “lots”, from the word “pur”) is a Jewish holiday that commemorates the deliverance of the Jewish people in the ancient Persian Empire where a plot had been formed to destroy them. The story is recorded in the Biblical Book of Esther (Megillat Ester in Hebrew).
Hanukkah, also known as the Festival of Lights, Feast of Dedication, is an eight-day Jewish holiday commemorating the rededication of the Holy Temple (the Second Temple) in Jerusalem at the time of the Maccabean Revolt against the Seleucid Empire of the 2nd century BCE. Hanukkah is observed for eight nights and days, starting on the 25th day of Kislev according to the Hebrew calendar, which may occur at any time from late November to late December in the Gregorian calendar. The festival is observed by the kindling of the lights of a unique candelabrum, the nine-branched menorah or hanukiah, one additional light on each night of the holiday, progressing to eight on the final night.
Tisha B’Av (lit. “the ninth of Av”), is an annual fast day in Judaism which commemorates the destruction of the First and Second Temples in Jerusalem and the subsequent exile of the Jews from the Land of Israel. The day also commemorates other tragedies which occurred on the same day, including the Roman massacre of over 100,000 Jews at Betar in 132 CE. Instituted by the rabbis of 2nd-century Palestine, Tisha B’Av is regarded as the saddest day in the Jewish calendar and a day which is destined for tragedy.