What would you like to understand?

A non-prefix-free code causes ambiguity because a received bit string can be segmented in more than one way into valid codewords. For Code 3, the received string 00 can be parsed as two copies of the codeword 0 (giving $x_1x_1$) or as one copy of the codeword 00 (giving $x_3$).

Conditions: Occurs when at least one codeword is a prefix of another codeword.; Illustrated here for concatenated received strings under Code 3.

A non-prefix-free code causes ambiguity because a received bit string can be segmented in more than one way into valid codewords. For Code 3, the received string 00 can be parsed as two copies of the codeword 0 (giving $x_1x_1$) or as one copy of the codeword 00 (giving $x_3$).

Conditions: Occurs when at least one codeword is a prefix of another codeword.; Illustrated here for concatenated received strings under Code 3.