Options are basically bets between 2 investors?

An option call is basically a bet between two people. One betting that the stock will go up while the other believes it will not.

That is true in its most simplistic form. However, there a more complex option strategies where both parties to the above transaction could want the stock to go up. For example, you buy the call and I sell it as part of a covered call or a vertical spread.

I can place an option call for example that will last 30 days or more?

There are about 4,200 stocks that offer options. About 500 of them offer weekly options for the next 8 weeks.

All optionable stocks will have the current month, the following month and the next two months in the cycle. Stocks (and ETFs) whose options are heavily traded may have even more expiration months.

If LEAPs are offered (long term options), there will be two subsequent January expirations as well.

Covered and uncovered is using your own shares as the betting material and using someone else's shares?

In the context of owning the stock, covered means using your own shares (a short position in a stock can also be covered). Using someone else's shares involves shorting the stock.

An option call is basically a bet between two people. One betting that the stock will go up while the other believes it will not.

That's the most fundamental / foundational understanding of an option contract (single).

However, those who short options may be doing so simply to acquire cash flow in the form of premium. They may not care about the final direction, or they might prefer the underlying's price to remain constant. If the strike price is slightly out of the money (OTM), then a slight appreciation might even be desirable, as long as the appreciated price doesn't exceed the strike.

There are also advanced options strategies that employ a compound conjunction of calls and puts with varying expirations and strike prices. These are known as spreads and iron condors, and they're available to anyone who can gain access to Level III Options approval. There are also at least six common types of butterfly spreads. In some of these strategies, notably iron condors, the owner of the security actually prefers that the price stays largely flat until expiration, with max gain achieved somewhere in the middle of a range of strike prices.

Still further, there are other so-called "delta neutral" (Δ) positions (besides iron condors) which are more complicated and completely agnostic to the underlying's movement.

I can place an option call for example that will last 30 days or more?

I don't get the question. (but I'll try anyway.) Conceptually and as well from a practically-speaking standpoint, of course you can. There are even options that span several years, which can give long call buyers more time for the underlying to exceed the strike price, but the further out the expiration, the larger the extrinsic time premium (θ) still built into the options, resulting in the upfront cost being sometimes prohibitive

Covered and uncovered is using your own shares as the betting material and using someone else's shares?

yes, covered = using your own shares as collateral

no, uncovered ≠ using someone else's shares

uncovered means that you're "naked" selling, a risky undertaking requiring Level IV Options approval. when naked selling a call, you secure your contract with nothing, which can lead to theoretically unlimited losses, since the underlying has no ceiling.

e.g. you sell naked a call good for 100 shares of Company Corp at a strike price of $105, for a premium of $2/shr = $200. the shares are trading at $100/shr. but before expiration, Company Corp reports earnings of $20/shr and consummates a strategic acquisition of Corporation Co., exciting investors and making the shares surge to $340/shr. the owner of a call contract at $105 strike calls their brokerage and asks to exercise the option.

"OCC randomly assigns exercise notices to clearing members whose accounts have short positions of the same series. The clearing member then assigns the exercise notice to one of its short positions using a fair assignment method, though not necessarily random. Ask your brokerage firm how it assigns exercise notices to its customers." source: here

Say you're the one that is fairly assigned. You would then need to buy 100 shares at $340/shr = $34000 in shares, and then sell those shares to the buyer of the contract for $105/shr = $10500, which means you just lost more than $22,000. You keep the $200 premium.

Obviously, this was an extreme example. But awful things like this can and have happened to people when they sell uncovered calls.

There's another scenario where you can 'bet' like that. It's called insurance.

I mean, at a simplistic level, insurance is a bet that you'll burn your house down, and the insurance company looks at probability, multiplies it by cost, adds a profit, and then sets a premium.

Your outcome is in not winning the bet - taking a small loss, to avoid a significant impact.

And that's a lot like how options work - they're very rarely just two investors having a bet between them. One party is - usually - using the option as a risk control.

The options market can therefore be seen as a sort of insurance market - where you take on risk, and earn a risk premium, because someone else wants to reduce risk (maybe by pooling it across a large number of counterparties).

At a simple example - imagine I run a bakery. I sell bread quite reliably every day, and am quite profitable, but only if the price of wheat stays pretty stable.

So I might take options on 'price of wheat' going up (I can either do this directly via commodity options or futures, or I can do this indirectly by taking options in companies that become more profitable in this scenario). I do that despite it not really looking like that's going to happen, and in effect waste money, "giving" it to the counterparty as a risk premium.

But in doing that, I know that I can stay profitable, even if there's a bad harvest this year - a situation which might otherwise put me out of business.

And the counterparty? On average (if they do this for many years) they make a profit - they're acting as the insurance underwriter here. Both parties notionally 'win' this exchange.

I win because I don't go bust if the price of wheat increases. You win because I'm paying slightly more than the 'actual risk' would reflect.