World championships in sports are generally held either annually or biennially, depending on the specific sport. For example:

• In gymnastics, the World Championships are held every year except Olympic years. After Olympic years, an "individual" Worlds event occurs without team competitions.

• In athletics (track and field), the World Athletics Championships started off being held every four years but have been held every two years since 1991, specifically in odd-numbered years to avoid Olympic years.

• The World Athletics Indoor Championships are held every two years, although there have been some exceptions, such as consecutive years 2003 and 2004, and a recent adjustment due to the COVID-19 pandemic.

Thus, the frequency varies by sport but is often annual or biennial, with some scheduling adjustments around the Olympic cycle.