Trilling and Chirping - what's the difference?

My kitty makes all kinds of fun noises and I always read on this board about other people's kitties that chirp and trill... But what's the difference between these two? How can you tell whether your cat chirped or trilled? When my cat makes noise, it would be nice to identify it as a chirp, trill, or plain old meow.

Unless people are calling a higher pitch brrr a trill, I think it's the same thing that people have different names for.

I just finished reading a chapter about cat vocalizations. A chirp, or chattering, or clicking is a sound a cat makes when his lowers jaw vibrates. Some experts seem to think it's an overflow of excitement or frustration at seeing prey and not being able to get it. It's a sound that is almost exclusively made when they see a bird.
Trilling is a form of a greeting. It is learned from the mother cat. She uses this sound when greeting her babies or calling them to her. Since it's a sound that is associated with love and affection, our cats often use it with us!!!

^But that doesn't make much sense for some cats. Some always make a short chirpy noise instead of normal meowing - I have such a cat. He's not making the chattering noise over birds, it's just a high pitch...well chirp. It sounds something between a bird chirp and him saying "oh oh oh". This is his general use meow for everything, it makes him look cute and he knows it.

And in the case of that book, they're calling the brrr noise a trill. If you want to further complicate this I have one that doesn't brrr, he makes low barely audible hrrrm noise. These noises are not just used in greeting, though. Many house cats will use this noise when excited, happy, or just as general use.

Since everyone calls the same noises different things, I prefer to use a more onomatopoeia method of describing them.

Of course with your own cats, your best factor for actually figuring out what vocalizations mean in each cat (each cat has it's own habits) is to watch your cat's body language and use it's current activity to help figure it out.

Tuppence trills and chirps with ease. AS with the saying 'a penny for your thoughts' so tuppence was named. From the outset she has vocalised her days. I have tried at times to rationalise our conversations, but who in their right mind would try to have a conservation with a cat? Tuppence trills as she comes to bed at 2 in the morning, she trills win she is just about to disembowel a new toy, she trills when I am in the shower, she trills at my iPhone and trills with joy when I flick the top of my diabetic needle across the floor, rattling across the floor. I have been a diabetic all of my life and now in my 'twilight' years it is a cat trilling her very joy of life that gets me out of bed.

I am watching her now. She is about to leap onto my desk and kill a tissue that is sitting on the corner. Trill or no trill the voice of a cat is wonderful. Warming, engaging, humorous and Tuppence full of another and special language. Tuppence chirps and trills. How lucky am I!