the unknown thing in between the tiles are starting to come out

especially in toilet and the tiles close to my stove

been googling around and found out the way fixing it is called GROUT

plan to DIY myself

went to nearby hardware shop, the chinese ah pek has no idea what is grout, but he suggest me to put cement gum

is it the same thing?

anything i should be aware of before i DIY?

the one they show it to me is "orange colour flour" type of thing

but google show otherwise, more like liquid form



now i am a bit confuse liao