Understanding the dynamics of partons in general, and non perturbative sea, in particular, will be
crucial for the understanding of strong interactions. Correlations of the spin of the target or/and
the momentum and the spin of quarks, combined with final state interactions define the azimuthal
distributions of produced particles. Production of correlated hadron pairs, in addition, will play
an increasingly important role in the interpretation of pion electroproduction data in general, and
hadronization process of quarks, in particular. More significant, than originaly anticipated, fraction
of pions coming from correlated di-hadrons, indicated by recent CLAS12 measurements,
and supported by various realistic models describing the hadronization process, may have a significant
impact on various aspects of data analysis, including the modeling, composition, and
interpretation of semi-inclusive DIS data, as well as calculations of radiative corrections. Studies
of the nucleon structure beyond the traditional leading twist and current fragmentation of inclusive
hadrons, provide qualitatively new tools to study the nucleon structure and extension of large x region
well covered by JLab, to large Q^2 at the EIC where it will be very important in interpretation
of the data from JLab.