I generally use garam masala for cooking chicken curry.
Recently I discovered that there is another thing called "Curry Powder" which is also used for cooking chicken curries.
What is the basic difference between curry powder and garam masala?
I generally use garam masala for cooking chicken curry.
Recently I discovered that there is another thing called "Curry Powder" which is also used for cooking chicken curries.
What is the basic difference between curry powder and garam masala?
Curry powder is used for spice, heat and flavour, whereas garam masala is used more for flavour and accent.
A general rule of thumb is curry powder is yellowish-brown whereas garam masala is greyish-brown. Curry powder will generally contain chilli and tumeric but not cardamom or cloves. Garam masala will generally contain the latter but not the former.
These spices are also used differently. Curry powder is generally fried with the onions and oil at the beginning of cooking, whereas the garam masala is added towards the end. Curry powder is much more "robust" than garam masala, while a good fry in oil will cause the flavours to bloom, the opposite would occur with garam masala as it is very delicate in flavour. If you cook garam masala for too long, the subtle flavours will disappear. This is not the case with curry powder.
Frequently, garam masala is added to milk and tea to make a gently spiced, flavourful drink. It would be unthinkable to use curry powder in this instance.
Just for posterity:
"Masala" means spice mix in Hindi, Nepali, and a couple other languages. "Garam masala" means "warming spice" and refers to any of a few dozen different mixtures of ground, and usually toasted, spices, frequently including cinnamon, cardamom, clove, star anise, cumin, and/or black pepper, but varying quite a bit across, cultures, regions, and kitchens, after being spread throughout Southeast Asia by trade. Many different masalas are used across India, Nepal, and Sri Lanka, of which garam is only one.
"Curry powder" is a modern Western (English, originally) invention to make replicating Indian "curries" easier. It is also a spice mix, frequently containing turmeric, chili powder, cumin, coriander, and other spices. The recipe varies between manufacturers, and recently even more, because as other masalas become popular worldwide, they are often labeled "curry powder". Further, some other non-Indian cultures have adopted curry powder and made their own distinct versions, such as Japan and Peru.
So, one difference is that an Indian home cook might use garam masala (depending on where they are from and what they are cooking), but would not use curry powder except out of desperation.
A second difference is that garam masala, as a mix, is rarely used as the primary spicing of a dish; it's usually added as supplementary spicing, often at the end of cooking.
A third difference is that "curry powder" generally contains turmeric and hot chili powder, while garam masala contains none. And garam masala usually has clove and caradmom, while curry powder rarely does.
The accepted answer is excellent, but just in case it's of use to you, I've always found a helpful analogy in home brewing.
Curry powder is like the bittering hops, added early in the boil for a bulk effect (bitterness and preservatives for beer, heat and basic body for curry). Garam masala is like the aroma hops, added very late in the boil for a subtle effect that would be lost if the volatiles were boiled off by extended cooking (hop aroma for beer, subtle flavours and complex notes for curry).
Someone more skilled with beer and curries than I could probably make an analogy about dry-hopping, but I'm going to leave it there.
Adding to the existing answers, there are regional differences to be taken into account. The Germans have a strong taste for fenugreek so the closer to Germany you are (Europe basically), the generic curry powder have a lot of fenugreek (besides the chili, coriander seeds and cumin) whereas your average garam masala mix have little to none. I've found this is so pronounced that what many Europeans associate with "curry flavor" is straight up fenugreek.