2. That which is needed for life, or needed in particular situations: "There are certain essentials that a person needs to know for success in this business."
Essential and Necessary are used interchangeably
The two terms refer to that which is indispensable or required for the completion or the accomplishment of something.
- Water is essential (or necessary) to sustain life of creatures both the greatest and the smallest.
- It is necessary (or essential) that the majority of citizens vote if they want to have a "government of the people, by the people, and for the people".
Essential is the stronger word because it means "pertaining to the very essence of existence". Necessary expresses a strong desire and can be some form of compulsion; however, essential implies that if something is not done, it can no longer exist.
2. Basic or indispensable; necessary: essential ingredients: "The cook considered garlic to be an essential component of his soup."
"Free speech is supposed to be an essential right of U.S. citizens."
3. In biochemistry, a substance that is required for normal functioning but cannot be synthesized by the body and therefore it must be included in the diet: "The doctor told him that he had to include essential amino acids in his food consumption."Electricity is both a basic part of nature and one of our most widely used global forms of energy
Electricity is actually a secondary energy source known as an energy carrier. This means we get electricity from the conversion of other sources of energy; such as, coal, nuclear, wind, water power, solar energy, etc.
These sources of energy for electricity are called primary sources and the energy sources used to make electricity can be renewable or non-renewable, but electricity itself is neither renewable nor nonrenewable.
Electricity use has resulted in dramatic changes in the way our world exists because before electricity became available over 100 years ago, houses had no light at night or people used candles, then kerosene lamps. Food was cooled in iceboxes (or not at all), and rooms were warmed by wood-burning or coal-burning stoves.
Many scientists and inventors have worked to decipher the principles of electricity since the 1600s and notable accomplishments were made by Benjamin Franklin, Thomas Edison, and Nikola Tesla.
Today, scientists are still studying electricity and learning more about it. They've learned that all citizens need to practice good safety habits, since electricity can be very dangerous.
Benjamin Franklin demonstrated that lightning is electricity, Thomas Edison invented the first long-lasting incandescent light bulb and Nikola Tesla discovered the principles of alternating electricity currents.
Before 1879, direct current (DC) electricity was used in arc lights for outdoor lighting. In the late 1800's, Nikola Tesla pioneered the generation, transmission, and use of alternating current (AC) electricity, which reduced the cost of transmitting electricity over long distances.
Tesla's inventions used electricity to bring indoor lighting to our homes and to power industrial machines.
In spite of the fact that electricity is important in the daily lives of people in industrialized nations, few probably stop to think what life would be like without electricity.
Regrettably, too many people in the world are still deprived of the pleasures and advantages of having access to electricity.
Like air and water, people who have normal use of electricity tend to take it for granted; even though they use electricity to do so many tasks every day; from lighting, heating, and cooling their homes to powering their televisions, kitchen equipment, computers, and other appliances run by electricity.
About the only time users of electricity really appreciate their electrical power and what it does is when it is cut off by storms or by some other abnormal situation.
- Proteins are the main structural component of tissue and organs and they are essential for the growth and repair of cells in the body.
- Carbohydrates are food groups that contain sugars and starches and they are the main energy sources required for metabolism or the chemical processes that take place within cells and they should make up at least half of people's diets.
Unrefined or unprocessed carbohydrates found in cereals and fruit are usually richer in fibers than refined carbohydrates; such as, sugar and white flour.
- Fats provide energy for metabolism and are a structural component of cells.
Saturated fats are found mostly in meat and dairy products and increase the amounts of unwanted types of cholesterol in the blood.
- Fibers are the indigestible structural material in plants and they are an essential part of a healthy diet.
- Water constitutes a high proportion of many foods and it is essential to maintain the chemical processes within cells and normal bowel functions.
- Vitamins ensure the healthy functioning of the brain, nerves, muscles, skin, and bones.
- Minerals consist of calcium zinc, and magnesium all of which are needed in small amounts to control cell metabolism and table salt is needed to maintain fluid balance.
2. Painful vulva.