Common ginger, Zingiber officinale, is a member of the family of Zingiberaceae, which comprises at least 800 different species.
The consumed portion of the ginger plant is the rhizome, often called “ginger root”, although it is not actually a root. The rhizome is the horizontal stem of the plant that sends out the roots.
There is a large number of variants (subspecies), which differ primarily in the smell and colour. The ginger is a monocotyledonous plant (that is, with the leaf to a single seed) of the tropics, that grows mainly in Southeast Asia.
It is a perennial herb, characterized by its very robust and fleshy rhizome with thin lateral roots.
Ginger is grown primarily in Asia and tropical areas and, in addition to its culinary function, has been used since ancient times for a variety of conditions, including colds, fevers, and digestive problems, and as an appetite stimulant. It is categorized by the U.S. Food and Drug Administration as a food additive but has been studied as a treatment for nausea and vomiting, as well as for arthritis.
Active molecules description
Ginger contains a number of pungent constituents and active ingredients. The major pungent compounds in ginger are active gingerols, which can be converted to shogaols, zingerone, and paradol.
The compound 6-gingerol appears to be responsible for its characteristic taste. Zingerone and shogaols are found in larger amounts in dried or extracted products.
Antiemetic activity: Suppressing 5-HT receptor. Nausea and vomiting are complex responses involving various neural pathways and motor responses to sensory stimuli; however, ginger and its constituents seem to function peripherally, by blocking 5-HT3 receptors – and most likely have an effect on other (cholinergic, vanilloid) peripheral receptors involved in smooth muscle contraction in the gastrointestinal tract.
Antioxidant activity: Nrf2 signalling pathway
Anti-inflammatory Activity: pro-inflammatory and anti-inflammatory cytokines- PI3K/Akt and NF-kB signaling.
Antimicrobial activity: Inhibiting biofilm formation. Affecting membrane integrity.
Neuroprotection: Anti-neuroinflammatory. Upregulating the level of NGF.
Studies on ginseng’s effectiveness in CINV 
It’s not known exactly how ginger works in the body to reduce nausea. Ginger contains oleoresins, substances that have an effect on the muscles of the digestive system. Ginger also has anti-inflammatory effects in the body.  
A 2012 study to evaluate the best dose of ginger also found a significant reduction in nausea among people who used ginger. In this study, patients were given a placebo or 0.5 grams, 1 gram, or 1.5 grams of ginger divided twice a day for 6 days and beginning 3 days prior to the chemotherapy infusion. The most effective dose in this study was 0.5 to 1.0 grams. 
Chemotherapy can cause nausea immediately, or over several hours and days following infusion. Another 2012 study done with breast cancer patients found that ginger was most effective in alleviating nausea that occurred between 6 and 24 hours following chemotherapy.  Yet another study performed on children and young adults with cancer found that ginger helped with both acute (within 24 hours) and delayed (after 24 hours) nausea associated with chemotherapy.
While ginger appears to help with nausea, a 2015 study found that ginger helped with nausea and episodes of vomiting but did not decrease the episodes of retching experienced by women with breast cancer. 
Results of a 2017 study published in the Annals of Oncology suggest that the effect of ginger on chemotherapy induced nausea and vomiting may vary between men and women, by cancer type, and by drug, making previous studies somewhat difficult to interpret.
 Treatment of Chemotherapy-Induced Nausea in Cancer Patients. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3188425/
 Efficacy of Ginger in Ameliorating Acute and Delayed Chemotherapy-Induced Nausea and Vomiting Among Patients With Lung Cancer Receiving Cisplatin-Based Regimens: A Randomized Controlled Trial. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6142108/
 Ginger (Zingiber officinale) reduces acute chemotherapy-induced nausea: A URCC CCOP study of 576 patients https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3361530/
 The Effectiveness of Ginger in the Prevention of Nausea and Vomiting during Pregnancy and Chemotherapy https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4818021/
 Ginger as a miracle against chemotherapy-induced vomiting. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3703071/