Take a look at your bag of Flour. You may find the type of Flour that stated on the front. Here's a simple list of Flour types and their uses:
(1) Bread Flour or Strong Flour
As the name implies this Flour is most suitable for bread making especially if you like a nice chewy bread. The Flour has a higher GLUTEN content of 12.5 - 13.5%. The Gluten content refers to the product of Water and Flour. The higher the Gluten content, the more elastic the dough. How do you know if you dough is elastic? Pinch a piece of your finished dough and stretch it. The further you can stretch it, the more elastic the dough. That means your finished product, Bread, is chewy unlike the crumbly texture of cakes or biscuits.
Someone asks me why do I not use Plain Flour in bread making? The main reason is the texture of the bread that cannot be achieved with just Plain Flour alone.
Note: You can use Brown or Wholemeal Flours for breadmaking too.
Now we go on to the most common Flour in the market.
(2) Plain Flour or All-Purpose Flour
This flour has medium Gluten content of 10-11.5%. It is generally used for cakes (unless recipe calls for Soft Flour), fritters and pastries.
Note: Self-raising Flour is a combination of plain flour and various raising agents. These include sodium and calcium phosphates, and sodium carbonate. I never buy Self-raising Flour as it's a plain waste of money if I have Baking Powder and Plain Flour at home. For each cup of Plain Flour, add 2 teaspoons of Baking Powder. Works fine for me!
(3) Cake Flour or Soft Flour
Containing only 5-8% Gluten, this Flour has the lowest Gluten content among all the flours. Best used for Chiffon cakes, Biscuits that call for very light crumb.
Just in case you are asking what on earth in Baking Powder.. here it is!
Baking Powder is not milled wheat flour but rather Two parts of Cream of Tartar combined with One part of Baking Soda.