What Is Cannabis? A Complete Beginner's Guide

Cannabis is one of the oldest cultivated plants on Earth, used for thousands of years as fiber, food, medicine, and a source of mind-altering effects. Today it sits at an unusual crossroads: scientifically complex, politically contested, and enormously popular. For newcomers, the vocabulary alone can feel overwhelming, with talk of cannabinoids, terpenes, indicas, and chemovars. This guide gives you a clear, grounded starting point, covering what the plant actually is, the compounds that make it work, how it interacts with the human body, and the main ways people use it.

What the Plant Actually Is

Cannabis sativa L. is a single botanical species — a fast-growing, annual flowering plant in the Cannabaceae family (which also includes hops). For most of history, taxonomists debated whether there were several species (C. sativa, C. indica, C. ruderalis), but modern genetics points to one species with a wide range of cultivated varieties.

The plant has distinct parts that matter to consumers:

• Flowers (buds): the resin-covered part people typically consume, where the active compounds concentrate.
• Trichomes: tiny, crystal-like glands on the flowers that produce cannabinoids, terpenes, and other compounds.
• Leaves: the iconic fan-shaped leaves, low in active compounds and rarely consumed.
• Seeds and stalks: used for hemp oil, protein, and fiber; they contain virtually no active cannabinoids.

Male plants produce pollen and are mostly used in breeding; female plants produce the resinous flowers that consumers and medical users prize.

Cannabinoids and Terpenes

Cannabis produces hundreds of compounds, but two groups do most of the work.

Cannabinoids are molecules that interact with the body's endocannabinoid system. The most important are:

• THCA / THC — the main intoxicating compound (more on THCA vs THC in a moment).
• CBD (cannabidiol) — non-intoxicating, associated with calming, anti-inflammatory, and anti-seizure effects.
• Minor cannabinoids — like CBG, CBN, CBC, and THCV, present in smaller amounts and studied for various effects.

Terpenes are aromatic oils that give each plant its smell — pine, citrus, pepper, berry, fuel. They are not unique to cannabis; the same molecules give lavender its scent and lemons their zing. Terpenes may also contribute to a plant's effects, a topic we cover in our entourage effect guide.

Hemp vs Marijuana

"Hemp" and "marijuana" are not separate species — they are legal and practical labels applied to the same plant based on THC content.

• Hemp generally refers to cannabis cultivated for fiber, seed, or CBD, kept below a legal THC threshold (commonly 0.2–0.3% THC by dry weight).
• Marijuana refers to cannabis with higher THC levels, grown for its intoxicating and medicinal effects.

This is a legal distinction, not a botanical one. The same species, bred in different directions, produces a fibrous, low-THC crop or a resinous, high-THC one.

A Brief History of Human Use

Humans have grown cannabis for at least 6,000 years. Early cultivation centered on hemp fiber for rope, cloth, and paper, and on seeds for nutrition. Medicinal and ritual use is documented in ancient China and India, where preparations were used for pain, inflammation, and spiritual purposes.

In the 19th and 20th centuries, cannabis spread through Western medicine — Queen Victoria's physician, for instance, prescribed it — before prohibition swept much of the world. The late 20th and early 21st centuries brought a renewed wave of medical and adult-use legalization, along with a surge of scientific interest in cannabinoids.

How It Interacts With the Body

Cannabis affects humans through the endocannabinoid system (ECS), a cell-signaling network found throughout the body. The ECS helps regulate appetite, mood, sleep, inflammation, pain, memory, and more. It has three main parts:

• Endocannabinoids — molecules the body makes itself (anandamide, 2-AG).
• Receptors — CB1 (mostly in the brain and central nervous system) and CB2 (mostly in immune tissues).
• Enzymes that break those molecules down.

Plant cannabinoids like THC fit into these receptors much like a key in a lock, which is why they can shift mood, perception, and appetite. CBD works more indirectly, influencing receptor activity and the breakdown of the body's own endocannabinoids. We go deeper on this in our endocannabinoid system and entourage effect guides.

Main Ways People Use Cannabis

Different methods produce very different onset times, durations, and intensities.

| Method | Onset | Duration | Notes | | --- | --- | --- | --- | | Inhalation (smoking, vaping) | Minutes | 2–4 hours | Fastest onset; vaporizing is less harsh than smoking | | Edibles and drinks | 30–120 minutes | 6–10 hours | Slow onset, stronger and longer-lasting effects | | Tinctures (under the tongue) | 15–45 minutes | 4–6 hours | Easier to dose than edibles | | Topicals (balms, patches) | Variable | Localized | Target skin and muscles; usually not intoxicating | | Capsules and pills | 1–2 hours | 6–10 hours | Consistent dosing; behaves like an edible |

Because onset and duration vary so widely, the method matters as much as the strain when it comes to the experience.

Key takeaways

• Cannabis is one botanical species (Cannabis sativa L.), even though it's marketed in many ways.
• Cannabinoids (like THC and CBD) and terpenes (aromatic oils) drive the plant's effects and character.
• Hemp and marijuana are legal labels based on THC content, not distinct plants.
• The plant works in the body through the endocannabinoid system, which regulates mood, sleep, pain, and appetite.
• How you consume — smoke, edible, tincture, topical — changes onset, duration, and intensity as much as what you consume.

Frequently asked questions