湯のみ (Yu-no-mi), a Yunomi is a Japanese tea cup with no handle and usually in tall cylinder shape. It is designed in this way so that when tea drinkers hold it, they will know whether or not the tea is too hot.
ぐい呑み (Gui-no-mi), a Guinimo is a small cup with no handles and usually meant for sake but you can still use it to drink tea. Because after all you can drink tea out of any vessels, as long as they could elevate your tea moment or fit your personal preference.