
The Biden inauguration is a crowd-free affair, with over 200,000 state and territory flags installed across the National Mall, to compensate for the people who will not be able to see the inauguration in person.

In usual circumstances, the US Chief Justice swears-in the president. But that's not mandated by the constitution. Any judge can administer Biden's oath.

None of the ceremonies - balls, and parades are prerequisites to swearin in, but have become customs over the years. None of this is mandated by the Constitution. For Biden to become president officially, he just needs to say the following words at noon of January 20 - "I do solemnly swear (or affirm) that I will faithfully execute the Office of President of the United States, and will to the best of my Ability, preserve, protect and defend the Constitution of the United States."

No, swearing-in with a Bible is not necessary, but is rather a custom. For instance, Theodore Roosevelt did not use a Bible during his swearing-in.

Biden called off his plans to arrive in Washington by an Amtrak train from Delaware. This was called off. In addition, people are being urged to stay away from the inauguration, also given the threat of not only COVID-19, but of rioters who had stormed the US Capitol on Janury 6. No inaugural balls are planned, with a TV production set to air.

All incoming and outgoing Cabinet members, lawmakers, and Supreme Court justices will attend the inauguration, along with VIPs. In a break from tradition, US President Donald Trump will skip the inauguration, but Vice President Mike Pence will attend it.

Currently, DC remains on lockdown owing to the threat of terror, and of course due to the ongoing pandemic. The National Guard remains on watch in the city, especially in the major regions. The only time the city remained under lockdown during the presidential inauguration was when Andrew Johnson was sworn in after the death of Abraham Lincoln.