A bull call spread, or bull call vertical spread, is created by buying a call and simultaneously selling another call with a higher strike price and the same expiration. The spread is profitable if the underlying asset increases in price, but the upside is limited due to the short call strike. The benefit, however, is that selling the higher strike call reduces the cost of buying the lower one. Similarly, a bear put spread, or bear put vertical spread, involves buying a put and selling a second put with a lower strike and the same expiration. If you buy and sell options with different expirations, it is known as a calendar spread or time spread.
Covered calls can make you money when the stock price increases or stays pretty constant over the time of the option contract. However, you could lose money with this kind of trade if the stock price falls too much (but can actually still make money if it only falls a little bit). But by using this strategy, you are actually protecting your investment from decreases in share price while giving yourself the opportunity to make money while the stock price is flat. 

So, call options are also much like insurance - you are paying for a contract that expires at a set time but allows you to purchase a security (like a stock) at a predetermined price (which won't go up even if the price of the stock on the market does). However, you will have to renew your option (typically on a weekly, monthly or quarterly basis). For this reason, options are always experiencing what's called time decay - meaning their value decays over time. 
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/
However, for put options (right to sell), the opposite is true - with strike prices below the current share price being considered "out of the money" and vice versa. And, what's more important - any "out of the money" options (whether call or put options) are worthless at expiration (so you really want to have an "in the money" option when trading on the stock market). 
For instance, it is possible to construct an option strategy in the futures markets that is affordable without sacrificing the odds of success...but with the convenience comes theoretically unlimited risk. This is easier than it sounds, similar to the way you would borrow money to pay for a house or a car, you can borrow money from the exchange to pay for long commodity option trades. There are an unlimited number of combinations of self-financed trades but they are typically going to involve more short options than long options, or at least as much premium collected on the sold options than that paid for the longs. In essence, the money brought in through the sale of the short options goes to pay for the futures options that are purchased. The result is a relatively close-to-the-money option with little out of pocket expense but theoretically unlimited risk beyond the strike price of the naked short options.

However, options are not the same thing as stocks because they do not represent ownership in a company. And, although futures use contracts just like options do, options are considered lower risk due to the fact that you can withdraw (or walk away from) an options contract at any point. The price of the option (its premium) is thus a percentage of the underlying asset or security.