Options are contracts giving the owner the right to buy or sell an asset at a fixed price (called the “strike price”) for a specific period of time. That period of time could be as short as a day or as long as a couple of years, depending on the option. The seller of the option contract has the obligation to take the opposite side of the trade if and when the owner exercises the right to buy or sell the asset. For more information, check out the Ally Invest Options Playbook here: https://www.optionsplaybook.com/
Just as you can buy a stock because you think the price will go up or short a stock when you think its price is going to drop, an option allows you to bet on which direction you think the price of a stock will go. But instead of buying or shorting the asset outright, when you buy an option you’re buying a contract that allows — but doesn’t obligate — you to do a number of things, including:
With straddles (long in this example), you as a trader are expecting the asset (like a stock) to be highly volatile, but don't know the direction in which it will go (up or down). When using a straddle strategy, you as the trader are buying a call and put option at the same strike price, underlying price and expiry date. This strategy is often used when a trader is expecting the stock of a particular company to plummet or skyrocket, usually following an event like an earnings report. For example, when a company like Apple  (AAPL) is getting ready to release their third quarter earnings on July 31st, an options trader could use a straddle strategy to buy a call option to expire on that date at the current Apple stock price, and also buy a put option to expire on the same day for the same price.
A longer expiration is also useful because the option can retain time value, even if the stock trades below the strike price. An option’s time value decays as expiration approaches, and options buyers don’t want to watch their purchased options decline in value, potentially expiring worthless if the stock finishes below the strike price. If a trade has gone against them, they can usually still sell any time value remaining on the option — and this is more likely if the option contract is longer.
Volatility also increases the price of an option. This is because uncertainty pushes the odds of an outcome higher. If the volatility of the underlying asset increases, larger price swings increase the possibilities of substantial moves both up and down. Greater price swings will increase the chances of an event occurring. Therefore, the greater the volatility, the greater the price of the option. Options trading and volatility are intrinsically linked to each other in this way.
If you are buying an option that is already "in the money" (meaning the option will immediately be in profit), its premium will have an extra cost because you can sell it immediately for a profit. On the other hand, if you have an option that is "at the money," the option is equal to the current stock price. And, as you may have guessed, an option that is "out of the money" is one that won't have additional value because it is currently not in profit.
According to Nasdaq's options trading tips, options are often more resilient to changes (and downturns) in market prices, can help increase income on current and future investments, can often get you better deals on a variety of equities and, perhaps most importantly, can help you capitalize on that equity rising or dropping over time without having to invest in it directly. 
What if, instead of a home, your asset was a stock or index investment? Similarly, if an investor wants insurance on his/her S&P 500 index portfolio, they can purchase put options. An investor may fear that a bear market is near and may be unwilling to lose more than 10% of their long position in the S&P 500 index. If the S&P 500 is currently trading at $2500, he/she can purchase a put option giving the right to sell the index at $2250, for example, at any point in the next two years.
Time Value: All options contracts have an expiration date, after which they become worthless. The more time that an option has before its expiration date, the more time there is available for the option to come into profit, so its premium will have additional time value. The less time that an option has until its expiration date, the less time there is available for the option to come into profit, so its premium will have either lower additional time value or no additional time value.
When buying a call option, the strike price of an option for a stock, for example, will be determined based on the current price of that stock. For example, if a share of a given stock (like Amazon (AMZN) ) is $1,748, any strike price (price of the call option) that is above that share price is considered to be "out of the money." Conversely, if the strike price is under the current share price of the stock, it's considered "in the money."