The word morning originally referred to the sunrise but today usually refers to the period of time just after one wakes up from sleep. Morning precedes daylight, evening and night in the sequence of a day.

Morning is the part of the day usually reckoned from dawn to noon. The name (which comes from the Middle English word morwening) was formed from the analogy of evening using the word "morn" (in Middle English morwen), and originally meant the coming of the sunrise as evening meant the beginning of the close of the day. The Middle English morwen dropped over time and became morwe, then eventually morrow, which properly means "morning", but was soon used to refer to the following day (i.e., "tomorrow"), as in other Germanic languages—English is unique in restricting the word to the newer usage. The Spanish word "mañana" has two meanings in English: "morning," and "tomorrow."

The most obvious manifestation of this meaning is in English speaking countries where the greeting changes from "good night" to "good morning" when midnight passes.

An oil field is a region with an abundance of oil wells extracting petroleum (crude oil) from below ground. Because the oil reservoirs typically extend over a large area, possibly several hundred kilometres across, full exploitation entails multiple wells scattered across the area. In addition, there may be exploratory wells probing the edges, pipelines to transport the oil elsewhere, and support facilities.

Because an oil field may be remote from civilization, establishing a field is often an extremely complicated exercise in logistics. For instance, workers have to work there for months or years and require housing. In turn, housing and equipment require electricity and water. Pipelines in cold areas may need to be heated. Excess natural gas may be burned off if there is no way to make use of it, requiring a furnace and stacks, and pipes to carry it from well to furnace.

Thus, the typical oil field resembles a small self-contained city in the midst of a landscape dotted with drilling rigs and/or the pump jacks known as "nodding donkeys" because of their bobbing arm. Several companies, such as BJ Services, Bechtel, Esso, Schlumberger Limited, Baker Hughes and Halliburton, have organizations that specialize in the large-scale construction of the infrastructure and providing specialized services required to operate a field profitably.

An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils.

First attested in English 1176, the word oil comes from Old French "oile", from Latin "oleum", which in turn comes from the Greek "ἔλαιον" (elaion), "olive oil, oil" and that from "ἐλαία" (elaia), "olive tree". The earliest attested form of the word is the Mycenaean Greek e-ra-wo, written in Linear B syllabic script.

Organic oils are produced in remarkable diversity by plants, animals, and other organisms through natural metabolic processes. Lipid is the scientific term for the fatty acids, steroids and similar chemicals often found in the oils produced by living things, while oil refers to an overall mixture of chemicals. Organic oils may also contain chemicals other than lipids, including proteins, waxes and alkaloids.

Lipids can be classified by the way that they are made by an organism, their chemical structure and their limited solubility in water compared to oils. They have a high carbon and hydrogen content and are considerably lacking in oxygen compared to other organic compounds and minerals; they tend to be relatively nonpolar molecules, but may include both polar and nonpolar regions as in the case of phospholipids and steroids.