What's the difference between water-based and solvent-based?

Water-Based Explained

These paints use water as their solvent making them more environmentally friendly. They typically dry much faster than solvent-based paints, are low odour and don't yellow as quick (or at all if Acrylic Paint is used). In most cases multiple coats can be applied in the same day speeding up the decorating process and they are also easy to clean up with soap and water. Also easier to touch up knocks and scratches.

Solvent-Based Explained

Solvent based paints (Also known as oil based paints) use organic solvents such as mineral spirits or turpentine to dissolve their binders and pigments. They dry slower than water-based paints, taking several hours or even days and have stronger odour so require more ventilation during the application and drying process. Generally they offer superior durability and are cheaper than most water-based alternatives if on a tight budget. A higher gloss sheen level is also easier to achieve with solvent-based paints. Cleans up using white spirit or turps.