After an unprecedented one-year postponement and the closing of the Olympics, the Tokyo Paralympics opened Tuesday night.

Tokyo became the first city to host the Summer Paralympics twice, after staging the 1964 edition. Since COVID-19 infections are increasing in Japan, the games will not have spectators, except for some students, and safety remains the priority of the organizers.

The following are questions and answers about the Paralympics, which will run through Sept. 5.

Q: What are the Paralympics?

A: The Paralympics are the largest global sporting event for athletes with disabilities. They are held after the Olympics close in the same host city and in many of the same venues.

The games held in Rome in 1960, with some 400 participants from 23 countries, are recognized as the first Paralympics.

(From L) Three-time Olympic judo gold medalist Tadahiro Nomura, torch relay official ambassador Aki Taguchi and actress Satomi Ishihara attend a ceremony at the State Guest House in Tokyo on Aug. 20, 2021, as the flames ignited in Japan's 47 prefectures and in Britain's Stoke Mandeville are merged into one for the Tokyo Paralympics. (Kyodo) ==Kyodo

Q: What are the sports to be held in Tokyo?

A: A total of 539 events across 22 sports will be staged in Tokyo and three nearby prefectures. Taekwondo and badminton will make their debut, while other sports include athletics, swimming, wheelchair basketball, wheelchair rugby and boccia.

The Paralympics have more medal events than the Olympics. Sports are divided into many events in order to create competition between athletes with similar degrees of ability.

File photo taken in July 2019 shows Markus Rehm of Germany competing in a Para athletics event in Gifu, central Japan. Germany's Olympic committee asked the International Olympic Committee to let Rehm, known as the "Blade Jumper," compete at the Tokyo Olympics as an exception in the summer of 2021. (Kyodo) ==Kyodo

Q: How many athletes are set to compete?

A: The Paralympics will involve a record 4,403 athletes from 161 countries and regions, as well as a small refugee team. Japan's delegation is made up of more than 250 participants, its biggest ever.

While Russia's athletes were banned from the 2016 Rio de Janeiro Paralympics due to the country's state-sponsored doping program, they can participate in Tokyo under a neutral flag.

British athletes taking part in the Tokyo Paralympics arrive at Haneda airport in Tokyo on Aug. 19, 2021. (Kyodo) ==Kyodo

Q: What are some of the COVID-19 countermeasures in place?

A: The organizing bodies of the Olympics and Paralympics have created a set of "playbooks" outlining anti-COVID-19 measures and responsibilities that all participants must follow.

Athletes need to take coronavirus tests on a daily basis, in principle, and will be isolated quickly if they are confirmed to be infected.

They will be kept in a "bubble" environment, separated from the Japanese public. They can only go to their venues and other limited locations, so sightseeing or visits to restaurants and bars are not permitted.

A medical examination room in the Tokyo Olympic and Paralympic athletes' village for those with a fever is shown to the media on June 20, 2021, amid concern over coronavirus infections. (Kyodo) ==Kyodo

Q: What are classifications?

A: Paralympic athletes are classified into sport classes depending on their degree of ability to ensure a level playing field no matter what type of impairment they have. The IPC says it is similar to separating female and male athletes in some Olympic sports or grouping them by weight classes.

While athletes' classifications are usually determined before the Paralympics, some of them will be decided by competitions in Tokyo due to the coronavirus pandemic.

Q: What are some of the different pieces of equipment used by athletes?

A: Athletes use different types of equipment depending on the sport and their disability, ranging from running blades to eye masks, racing wheelchairs and high-tech handcycles. Technological advancement has helped athletes reach higher and higher levels of performance over the years.

There are even repair centers at the athletes' village and some venues for participants' equipment.

Japanese wheelchair tennis player Shingo Kunieda takes part in an official practice session for the Tokyo Paralympics on Aug. 22, 2021, at Ariake Tennis Park. (Kyodo) ==Kyodo

Q: What are the origins of the Paralympics?

A: The Paralympics have a relatively short history. According to the International Paralympic Committee, a competition for World War II veterans on wheelchairs held in Britain's Stoke Mandeville in July 1948, coinciding with the opening of the London Olympics, is considered the origin.

The competition organized by Ludwig Guttmann, a doctor who opened a spinal injuries center for veterans at a local hospital, evolved into the Paralympics.

Paralympic gold medalists Susie Rodgers (L) and Jane Blackburn (R) attend a flame-lighting ceremony in Stoke Mandeville, a village in southern England that is considered the birthplace of the Paralympic Games, on Aug. 19, 2021, ahead of the Aug. 24 opening ceremony of the Tokyo Paralympics. (Kyodo) ==Kyodo

Q: What were the 1964 Paralympics in Tokyo like?

A: While they were called the International Stoke Mandeville Games, the name Paralympics was used extensively at the time to refer to the event, which featured some 370 athletes from about 20 countries competing across nine sports.

The games, held less than two decades after Japan's defeat in World War II, have been considered the turning point in sports for people with disabilities in the country.

Katsumi Suzaki (C) takes part in a men's wheelchair basketball event during the previous Tokyo Paralympics in November 1964. (Photo courtesy of Japan Sun Industries)(Kyodo)