Blocks are wooden, plastic or foam pieces that are similar to bricks and children make towers, and other items by joining them, they are used majorly for stacking and making some item. This develops in the child the basic skills of how to make a wall, or how to build. These are the first skills that the child learns and are very good throughout early childhood as the child takes on more and more complex blocks like Lego, Magna-tiles etc.
Manipulatives come in all types of shapes, mainly in plastic, and develop fine motor skills and help in the brain neurons growth as every time the child starts thinking about how to create further, it develops the brain thinking abilities, so these are very essential for the child in the formative ages like from 2 to 5 yrs.
Puzzles are basically either wooden, cardboard or foam, and essentially are to be joined together, starting with basic 3pc to 6pc puzzles and going right upto 1000pc puzzles. They develop the innate ability of the mind to put together the whole picture as per the photogenic memory that the mind has about the item, so while a child of about 2-3 years starts with 3pc to 6pc puzzles, the child at 5-6 yrs does about 20pc to 60pc puzzles, and so on, if adults also do puzzles their memory will remain sharper for longer.