The Orthodox say that as they encounter contemporary society and its technology, the Torah and Talmud (interpretations of the Rabbis) must be maintained in through practices.
The Orthodox take the Mitzvot (commandments) very seriously. There are 613 but some do not apply because they refer to the Temple. The Temple was destroyed in 586 BCE for the first time by the Babylonians and the second on in 70 CE by the Romans. Some of the strongest effects of the commandments refer to the Shabbot (sabbath) and not working. Work is tightly defined. As new technology appears, Rabbis need to take decisions.
Orthodox Jews, for example, cannot put a light on during the Sabbath. For 25 hours lights used to burn continuously. Now a timer switch can put them on and off, from evening to daylight to evening. However, there is also a commandment against making fire during the sabbath. Some people thought this meant electric lights could not come on, but it was decided by the rabbis that they can burn.
Rabbi Sampson Raphael Hirsch (1808-1888) attempted to combine Judaism with modernising Western culture, especially in Germany, and his ideas spread around Europe as repression took place in the 1930s. Nevertheless he maintained the principle observances in the Torah and Talmud and thus his view became that of the mainstream Orthodox who applied Judaism to society rather than have society compromise Judaism and its fundamentals.
Against this the Ultra-Orthodox do not apply their practices to the moder world. They believe that the sacred canopy of the Middle Ages was the most suitable time for the wider cultural support to their faith. They combine therefore something of the Middle Ages Judaism with learning and enthusiasm keeoing to intense and minutely detailed traditions, whatever the modern world may think.
The Orthodox practice the full range of rituals and festivals through the year. Most descriptions of Judaism are about Orthodox Judaism.