The normal budgie is one whose markings match with the wild type budgerigar. The budgie can be any of the basic body colours, but so long as it has the wild type markings it will be of the normal variety. So you can have skyblue normal, grey normal, dark green normal.... etc. Firstly, lets look at a wild budgie, pictured below on the right. We specifically need to focus on the markings to get an idea of what normal markings are.
From the forehead and down the back to between the wings they have black and yellow stripes. The feathers on the wings are blackish with yellow edging, with the long flight feathers being black, with a thick yellow bar along them that is only visible when the wings are extended. The primaries, and some of the lesser flight feathers, have a lovely green tint only visible in certain positions. The long tail feathers are a lovely dark teal blue, with the tail coverts having a thick yellow bar through them.
If you are not sure what any of these descriptive terms mean, please visit the Budgie Anatomy page.
As mentioned above, the normal budgie can come in all the basic body
colours; light green, dark green, olive, grey green, violet green,
skyblue, cobalt, mauve, grey and violet. None of these body colours
change the pattern of the budgies markings, but the different shades do
alter the colour of the tint on the flight feathers. This is a useful
feature if you are trying to determine what shade your budgie is, but
more on that on the budgie body colours page.
markings can also be combined
with other varieties that alter the colour of those markings, to
many beautiful birds; cinnamon, greywing, clearwing, dilute, fallow and
golden face, to name just a few. Remember, if the markings are in the
same pattern as a wild budgie, then the bird is still a normal, but if
the pattern of the markings is changed, then you have moved into another
Basically any bird that still has the wild type markings is a normal, so you can have a normal cinnamon or a normal yellow face blue etc. It is usual just to skip using the term normal, and refer to them simply as a cinnamon or a yellow faced blue, for convenience though.
Below we have a grey green normal on the left, and a skyblue yellow face 2 normal on the right.
The normal budgie is the standard by which the inheritance of other colours and varieties are described. If a variety is recessive it means that it is recessive to the normal (the wild type) form. If it is dominant it means it is dominant to the normal form.
So to describe how the normal is inherited you really need to know how the variety it is breeding with works. Take a look at the other varieties to understand how they react with it.