"A climax of sexual excitement". That is called an "orgasm".
Some say "it's like a wave of pleasure coming from down there and bringing me up to an explosion."
Or "my muscles shrink and tingle everywhere. I cannot help but to lean backward and get into spasms with spectacular sensation."
Or "A blackout. I cannot move for a while."
Or "It's literally 'COMING'. Slowly from inside of my body, and springing out with my peak cry."

Sounds like something big and utterly desirable.

"But... I've never experienced one before..."

First of all, it is not an easy thing for women to get an orgasm. 50% of women have never experienced orgasm with penetration. So it's quite a normal thing if you have not yet go there. On the other hand, women can get an orgasm with clitoral stimulation quite easily. Is there any difference?

Level of Orgasms

Let's see the level of orgasms. It is said that a penetration orgasm is about 2 - 3 times more intense than a clitoral orgasm. And the cervix orgasm is even more, and some women will faint from this powerful orgasm. However, you need to develop your body with your partner until you reach to those orgasms.
(Please note that the orgasm is totally depends on each woman and there's no such thing as a benchmark. These are only references from past research.)

Find your pleasure zone

First, you need to know where those erogenous zones are located. If you cannot tell, your partner will never know (unless he's a sex master). And if you can tell, you will never think you are sexually insensible.

The Clitoris would be easy to find since it is located outside of the vagina and can be reached by yourself without difficulties.
To find it, you can pull the labia upwards to open it. Then you will see there's a small skin hood in the middle. The clitoris is usually hidden under this thin skin hood. Try to stimulate this point with your finger, a vibrator or even a shower. DO NOT touch roughly as it's just hurting. Slowly and gently. If the friction hurts you, use a water-based lubricant or your own secretion. This is the most sensitive part of the entire female body and it responds to sexual arousal by filling with blood. So from anatomical and orgasm point of view, it is usually considered as the female equivalent of the head of the penis.
Clitoral orgasm is a basic and a starting line for further stages. Try to aim at this first.

Recommended C-Spot Vibrators

The G-spot is named after its discoverer, a German gynecologist called Ernst Grafenberg. It is suppose to be located about 2 - 5 cm deep inside the vagina, belly side of the vaginal wall. It is usually difficult to find because there's no obvious mark. Furthermore, every woman may have a different G-spot location. So a man who once found this with other woman tends to stimulate the same spot in the same way, which is mostly wrong.
To find the G-spot, you need clitoral stimulation first. When you touch the clitoris, it becomes bigger with blood but after a while, it will be hidden inside. Then you can search the G-spot. It can be said that G-spot is the other side of the clitoris. You need to press firmly the vaginal wall since the spot is not on the surface. If it's difficult, try to stimulate the clitoris in the same time.

Recommended G-spot Vibrators

P-spot and A-spot are usually found only by women who have already experienced C-spot and G-spot orgasms. Normally women will feel discomfort when the penis touches their cervix. Especially when they don't have enough experiences. So to develop these spots, you will need a constant inquiring mind.
Now clean up your finger, cut your nail, lubricate it and insert gently to the vagina. When your fingertip touches something hard like a cartilage, that is the cervix. If you have already given birth, it would be a little softer. A-spot or AFE-zone (Anterior Fornix Erogenous Zone) is located next to the cervix, on the bladder (belly) side.
And contrary, P-spot or PFE-zone (Posterior Fornix Erogenous Zone) is behind the cervix, on the rectum side. It's quite deep inside so that you need a longer vibrator or with your partner, you could feel it in back position.
Not like C-spot or G-spot, it is said that they are not simply erogenous spots but the good points to make a leverage to shake the uterus and other organs. When you try with your partner, the usual piston movement is not good enough or even hurting. Try a slow circle and shaking movement with a position that his penis can reach to cervix. And that will reach to a violent orgasm.

Has age an affect on the orgasm?

The answer is "YES" and "NO". Usually older aged women can reach to the orgasm more easily and that is simply propotional to their experience.
When you are young, you might be scared, nervous, or even feel guilty to have a sexual pleasure. But once you are more experienced, you will get more confidence in bed, which brings you even a better sex experience. So once you have sexual self-esteem and try to brush up on your sensitivity, age actually doesn't matter.