1. Introduction
2. Methodology
2.1. The VANDELS spectroscopic survey
2.2. Line measurements
2.3. Systemic redshift estimations for CIII] and HeII line emitters
2.4. Identification and exclusion of AGNs
2.5. Stacking analysis
2.6. Probing the ISM kinematics with absorption lines
2.7. The combined fit of low-ionisation lines
2.8. The maximum ISM velocity
2.9. Galaxies with positive ISM velocity shift
2.10. Fitting the SiIV doublet
2.12. Morphological analysis
3. Results
3.1. Dependence of the bulk ISM velocity on galaxy properties
3.2. Dependence of the maximum ISM velocity on galaxy properties
3.3. Outflows in mergers and redshift evolution
4. Discussion
4.1. Comparison with works at lower redshifts
4.2. Outflow physical properties and mass loading factor
4.3. Low- versus high-ionisation gas outflows
5. Summary and Conclusions