Parton Distribution Functions and the role of forward region data

In the era of searching for new discoveries at the LHC, it is crucial to achieve a higher level of precision in understanding the proton structure which will allow for unambiguous interpretations of the high energy, luminous data ahead. The knowledge of proton's constituents comes mainly from the deep inelastic scattering data at HERA, complemented by the measurements from the fixed target, Tevatron, and now increasingly precise more data from LHC. A road-map that marks the most recent developments from the past and present experiments sensitive to the proton constituents will be presented here with an emphasis on the recent results using LHC data from the forward region.