Why "supercede" needs to take a seat

What kind of error is it?

It is a common spelling error.

Why do people make this mistake?

People often make this mistake because they associate the word with other verbs ending in "-cede", such as "precede", "recede", and "concede". This leads to the assumption that "supersede" follows the same spelling pattern. However, "supersede" is derived from the Latin word "supersedēre", where "sedēre" means "to sit", not "to go" as in "cedere". Therefore, the correct spelling uses "sede" rather than "cede".

What is correct?

"Supersede" is the correct spelling. It means to replace something older or obsolete, or to take the place of something else in power, authority, or importance.