Particle boards and blockboards are two very different types of engineered wood products. The major points of comparison are listed below.
Difference in Composition
Particle boards are made by glueing together very small chips of wood (particles of wood) and sawdust to each other using phenolic resins, and pressing the mixture firmly together to form flat boards.
On the other hand, blockboards are made using solid rectangular blocks of wood laid side by side and joined end to end, and covered on either side by layers of thin plywood sheets. The blocks used are usually softwood (using pine wood blocks is very popular in India)
It can be quite safely said that blockboards are stronger and more durable than the low density particle boards. Blockboards are sometimes also used as an alternative to plywood when longer pieces such as for bookshelves are required to be used.
Ease of working
Working with blockboards is also much simpler than with particle boards, since the traditional methods of using nails as well as screws works with it. On the other hand particle boards need only screws and working with it using traditional wood working tools is quite difficult.
Difference in lamination
Particle boards are usually laminated at the time of their manufacture (pre-laminated particle boards) while decorative laminates need to be separately glued to the blockboard as is done in the case of plywood.
The cost of blockboards will be higher than that of particle boards but still it is lesser than the cost of plywood sheets of the same size.