When people talk about Celine Dion, terms like "singer,'' "entertainer'' or "pop star'' no longer suffice. She is . . . a diva.

It used to be that being called a diva meant you had made it as a singer. The term was reserved for those who possessed exemplary voices and personas that were not merely pleasant, but touched the soul, mirrored the human condition, elevated the listener to a higher plane.

And Dion does just that.

So do Whitney Houston, Gloria Estefan, Aretha Franklin, Bette Midler, Barbra Streisand and Mariah Carey. Celia Cruz does it in Spanish. Nana Mouskouri does it in every language.

And then there's people like the Spice Girls, Brandy and the women of Lilith Fair. They are often called divas but don't deserve the title. Few do.

The pop diva, you see, is a special creature. She must have an exquisite voice, the demeanor of a queen and the personality of Xena, the Warrior Princess, tempered with, perhaps, Lady Diana.

Take Aretha Franklin, a woman whose formidable instrument is matched by her formidable presence. Her singing? Sheer exuberance. One joyous, church-inflected phrase after another that immediately draws people to their feet. Then: a soulful lament that reduces them to tears.

Her nearly 40-year recording career makes her the senior stateswoman of divas. When VH1 produced a Divas special earlier this year, the other participating divas -- Carey, Estefan, Dion and Shania Twain -- all demurred to Franklin by going to her dressing room for a rehearsal of (You Make Me Feel Like) A Natural Woman.

The song, the grand finale of the live TV show, highlighted the wide spectrum of today's pop divadom.

Dion is the most popular one of the moment. Her strength lies in the sometimes over-dramatic emotion she puts into her five-octave vocals. On stage, she oozes pathos, her hard work at odds with her designer dresses and queenly posture.

Carey, 28, the youngest of the bunch, has a streaming, R&B- and funk-infused voice that ripples through the notes with seemingly far more ease and decidedly more subtlety than even powerhouse Dion. She is a coloratura soprano, one who can shape a single note in many different ways, able to turn the simplest phrase into a virtuoso exercise. She is also one of the few divas to write her own material, although this, in no way, is a requisite for divahood.

The word diva, which derives from the same feminine Italian term (there are are no divos), means "goddess'' or "divine.'' It's a term most closely associated with great opera singers, and rightly so. Diva is synonymous with "prima donna,'' which the dictionary defines as "the principal female singer,'' or "an extremely vain, sensitive or difficult person.''

And when one person came along who embodied all these definitions? Well, there you had a true DIVA, like the late opera star Maria Callas.

But divahood isn't and shouldn't be the exclusive privilege of classical music. Great talents, after all, take different paths.

Take Estefan, who has had less classical training than many of her pop diva contemporaries. But when La Estefan gets onstage, she is dynamite -- a singer and dancer whose Latin rhythms make her an exception in the pop diva world. No diva can make you boogie like Estefan, who also writes much of her material, sometimes with memorable results (as with Mi Tierra.)

And then there's Twain, who was invited to participate in the VH1 special thanks to her status as the current goddess of country. But with success hinging on videos rather than performances, and a voice that doesn't come close to her contemporaries -- Carey and Dion -- her induction into the diva hall of fame remains hardly assured.

Less impressive -- and her fans surely will dispute this -- is Streisand, who sings within a very limited range, though one that she handles superlatively. It was Streisand who redefined the diva look. Her long nose, she declared, would not be sacrificed for it might affect her vocal chords. Today, even when Streisand is silent, she looks magnificent.

And then there is Houston. She possesses the most beautiful voice of all: a soaring soprano, powerful, technically superior, simply glorious. She can phrase like an opera singer, but has the look of a movie star -- which, of course, she has become. Too bad that she is reputed to have the personality of . . . a diva.