There's different branches of social care, some deal with child protection issues, some with vulnerable adults, some with children with learning/behavioural difficulties, some with disabilities and some with the elderly.

As for the why, it's because some sections of society have less of a 'voice' than others and require extra support.

the english organisation im going to work for soon, works at geting drug addicted teens off the streets, off of drugs, into education, housing and employment.

They need help becoz of the drug culture and general apathy of thier parants and freinds, the govermant wants to stop this

They help the elderly getting them meals on wheels,home helps and if they go to a pensioners club a free bus is provided.

They deal with things like children who are being abused or not taken care of properly, taking them into foster care or childrens homes.