1. Introduction
2. Observations and data reduction
2.1. Observation status
2.2. Direction-independent calibration
2.3. Direction-dependent calibration and imaging
2.4. Mosaicing and radio source cataloguing
3. Image quality
3.1. Source extensions
3.2. Astrometric precision
3.3. Accuracy of the flux density scale
3.4. Dynamic range
3.5. Sensitivity
3.6. Completeness
4. Public data release
4.1. Mosaics and raw PyBDSF catalogue
4.2. Source (dis-)association and optical counterparts
4.3. Photometric redshift estimation
5. Future prospects
5.1. Reducing image artefacts
5.2. Exploiting the large fractional bandwidth of LoTSS
6. Summary