The South Bank of London usually describes a length of the South side of The Thames between Lambeth and Southwark, though some people would disagree with my imperssion! That’s what the South Bank means to me, anyway.
The South Bank has some very interesting features, such as the South Bank Centre (theatres, concert halls, exhibitions), Shakespeare’s Globe Theatre, Southwark Cathedral, Borough Market, Jubilee Gardens, London Eye, London Bridge, and many galleries, museums and restaurants. It is about 3.5km from London Eye to Tower Bridge.
One short stretch of the South Bank is called Bankside; the area west of Southwark: