"Zen" or "Ch'an"?
People sometimes wonder what, if any, difference there is between Ch'an and Zen Buddhism. While both have their roots in the Dhyana school which originated in India when the Buddha held up a flower and Mahakasyapa received the first "Mind to Mind" transmission of the Dharma, there are differences that have evolved over time as the schools developed in different cultures and were influenced by different local traditions.
Zen is the Japanese transliteration of the Chinese word Ch'an, which is a transliteration of the Sanskrit word Dhyana. The closest English definition of this word would be "to dwell", but we have come to accept the word as meaning basically "meditation". So Zen, Ch'an, and Dhyana are all fundamentally "Meditation Schools" of Buddhism. Those are the similarities, now for the differences.
While Buddhism was really introduced to China in the first century c.e., it didn't really take the form we call Ch'an until the arrival of Bodhidharma around the year 520. Bodhidharma was a proponent of "Wall gazing" meditation , and this Buddhism with it's primary focus on meditation was introduced into South China where Daoism had a long and beautiful history - the two developed into what I feel is the kind and gentle Ch'an school. When Master Hsu Yun (Empty Cloud) reunited the five Ch'an sects back into one recognizable tradition, he taught the Pure Land methods in conjunction with the meditation and Kung-An/Hua-Tou methods, and the resulting unification is what many of us who consider ourselves his disciples now call Ch'an Buddhism.
Buddhism arrived in Japan somewhere around 550 c.e., but it wasn't until some six hundred years later that it was codified into what we now call Zen, and the three or four different schools thereof. Soto Zen (Dogen), Rinzai Zen (Eisai), and Obaku Zen. Zen in Japan in my opinion is very formal, and somewhat more rigid than is Ch'an in China. Both are beautiful ways to practice the Buddha's Dharma.
There is yet another Zen school, from Vietnam (Thich Nhat Hanh), which is in my opinion softer and gentler even than the Ch'an of China. But that's another story.
I don't posit that any one of the Zen/Ch'an/Dhyana/Son schools is superior to any other. Only that Ch'an is the one that I found to fit me personally. On that same note, I don't hold that any of the Mahayana traditions are superior to the Theravada or the Vajrayana traditions either. It's all a matter of personal preference. The Buddha gave us 84,000 doors. Choose one and see if it works for you!