What is a ha?

Ha is the abbreviation for hectare, which is the unit of measure for agricultural land.
A hectare is 100x100m, or 10 000 square metres. This is about the size of rugby field.

What is a cultivar or cv?

Cultivar is an acronym standing for "cultivated variety" and refers to variety found within a specific crop, e.g. fruit, wheat, etc. They are normally developed by humans for increased production or resistence to disease or better quality.

An example:
Here, you can see four different varieties of apple: each of them are different in terms of colour, taste, and even use! Granny Smith apples are, for instance, fairly tart to the taste, but they are excellent baking apples, and are delicious as a warm dessert with raisins and custard. Star King on the other hand is a lovely apple to eat, but tends to become floury when baked.

Granny Smith

Star King

Golden Delicious

Pink Lady