What is CAMHS? and yes I know what it stands for...?

I know it's some sort of counselling, but basically, i went doctors about depression, got referred to CAMHS they referred me to relate counselling, then i had to go back to the doctors after being confessing to my counsellor about feeling suicidal and self-harming again, so got referred to back to CAMHS again, so now I'm seeing a counsellor or something from there instead, I have had this explained to me a few times, but i just can't concentrate on what they're saying and keep zoning out, so now I'm just confused... what is the difference?!