Why is Capital account always given a credited, or why is capital considered as a liability. Please correct me if I am wrong.

It is correct that capital is treated as liability for a business. this is because of the Business Entity Concept which assumes business has a distinct and separate entity from its owners. It means for the purpose of accounting, business and owners are to be treated as two separate entities. So, When a person brings in some money as capital into his business, in accounting records, it is treated as liability of the business to the owners. It is assumed that one separate entity(owner) is giving money to another distinct entity (business unit).