regex - what does sed 's#/text##' mean? -

i've encountered sed expression , not figure out means. i've performed google search previously. i'd appreciate help. initial # , final ## mean?

sed 's#/text##' 

this replace "/text" null "", try below gives blank

echo /text| sed 's#/text##' 

initial # sed delimited replace , middle # seperator between first string replace, , last # last delimiter sed

its same regex/replace sed command