Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Erika Rasure is globally-recognized as a ...

Steve Nix is a member of the Society of American Foresters and a former forest resources analyst for the state of Alabama. Leaf shapes play an important role in tree identification, providing key ...

Janet Berry-Johnson, CPA, is a freelance writer with a background in accounting and income tax planning and preparation for individuals and small businesses. Her work has appeared in Business Insider ...

Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...

H&R Block's e-filing products are intuitive and easy to use. For paid users, tax pro support is available via screen share or chat. Many, or all, of the products featured on this page are from our ...

The immune system is a complex network that finds pathogens, removes damaged cells, and launches immune responses to protect the body from infection. White blood cells drive this defense: phagocytes ...

The nervous system consists of the central nervous system (brain and spinal cord) and the peripheral nervous system (motor nerves, sensory nerves, cranial and spinal nerves, autonomic ganglia, and ...