Majha
The partition split the Punjab Province (British India) into the two states of West Punjab (Punjab, Pakistan) and East Punjab. However, the historic Majha region is arguably still the same as before since the partition does not change the previous history of Punjab, therefore does not change the geography of the Majha region of the historic Punjab region.
West Punjab
Today the term Western Punjab is used in Pakistan to describe the whole part of Pakistan's Punjab province except the Lahore/Central Region, while in India it is often used to refer to the entire Pakistani Punjab.