"Heroin" vs. "morphine": words of potent impact

What is similar?

Both heroin and morphine are opioids derived from the opium poppy and are used for pain relief, although heroin is illegal in most countries while morphine is used medically. They can both be addictive and have similar effects on the brain, leading to increased tolerance and potential for abuse.

What is different?

Heroin is typically more potent and acts faster than morphine. It is illegal and is often used recreationally, whereas morphine is a legal prescription medication used primarily for treating severe pain. Heroin is often prepared as a white or brownish powder or a black sticky substance known as black tar, while morphine is available in pills, injections, or as a syrup.

Which one is more common?