The escape character on the command line is the backslash. When it precedes a meta character in a pattern it causes that character to be taken literally. That character loses any special significance it might have normally had.
Following a backslash by two hexadecimal characters in a pattern or translate string results in a single character with the hexadecimal value specified. For example \0A is the single character whose hexadecimal value is 0A (a linefeed character).