The thyroid is a butterfly-shaped organ that sits on the front of the neck. It lies below Adam's apple, along the front of the windpipe. It has two side lobes connected by a bridge(isthmus) in the middle.
When the thyroid is its normal size, you can't feel it. It is rich with blood vessels, hence the brownish-red colour. Thyroid hormones influence metabolism, growth and development, and body temperature.