Prif ddiben y Gyllideb Atodol hon yw dangos y newidiadau cyllidebol ers Cyllideb Atodol Gyntaf 2017-18 a gyhoeddwyd gan Lywodraeth Cymru ym mis Mehefin 2017.
It sets out a number of allocations from the reserves, details changes in and transfers between Ministerial portfolios and includes revised Annually Managed Expenditure forecasts.