How do caraway and ajwain differ in taste and use? These two seed spices seem confusingly similar. I have never used ajwain before. A new recipe I intend to try out calls for jowan (carom seeds) which, according to Google and Wikipedia, are also called ajwain. The pictures I found online of ajwain resemble fennel and caraway seeds but seem smaller than either. Since there are two different Wiki pages for caraway and ajwain, I was certain they were different things. 

Today I saw a pack of ajwain at an Indian grocery store but "(caraway)" was also printed on the packaging. As per Wikipedia, ajwain is also called ajowan caraway. But how different are they?


How are they different in taste and actual use?  
If I don't have ajwain what'd be a good substitute?
Ajwain is a plant in the family apiaceae, and its seed, which is used (especially in south Asian cooking) for its thyme-like flavor while caraway is a biennial plant, native to Europe and Asia, mainly grown for its seed to be used as a culinary spice. 

Ajwain is used more for saviory dishes for it's thyme like qualities, while caraway is more used in baked goods similar to how aniseed is used.