# Distance and number of corrected errors in quantum error correction [duplicate]

In Gottesman's introduction, it writes

A code that corrects t errors is said to have distance 2t + 1, because it takes 2t + 1 single-qubit changes to get from one codeword to another.

Other reviews have slight different definitions but I think they are all equivalent. I am still new to QEC...and a little confused about how these $$2t+1$$ single-qubit changes take place during quantum error correction..Could anyone give a more detailed explanation?

Thanks!