What is tefilah? Is it turning pages? Even a horse can be taught to turn pages. There once were two polish noblemen, one of which had a Jewish advisor who he though could do anything. One day, when the noblemen were drunk, they bet on whether or not a horse could be taught to pray. The nobleman went to his Jewish advisor and told him of the bet. The advisor took a horse and placed oats between the pages of a book. The horse learned to turn the pages in order to get the food. When he was observed, it looked as though he was praying.
Kavanah is what makes tefilah.
Kavanah is a feeling. It is an inner feeling that makes your tefilot real. Kavanah means that you put your whole heart and soul into each word; you try to please G-d with your prayers. Kavanah transforms the prayer from the siddur into your own personal tefilah.
The best way to explain kavanah is through a story. There once was a cantor, Moshe, who had a beautiful voice. It happened that one Shabbat, as Moshe was carrying the Torah in his arms, his voice was more beautiful than ever. Up in heaven, where G-d was listening to the singing of Israel, Moshe's voice rose above all the others. Suddenly, the Torah began to rise and lift up Moshe. It carried him up to the sky until he stood before G-d. God asked him, "Moshe, what gives your words the power to reach my throne?" Moshe answered, "When I sing to you, G-d, I see all the words before my mind's eye; I taste each word before it leaves my mouth; I allow it to ring in my ears and I try, above all, to understand it." To this G-d replied, "This is true kavanah," and He returned Moshe to his congregation.