Hi steemians. Take care yourself and your beloved ones in this worst situation of Covid-19.I wish you all will remain safe.
Thankx dear @yousafharoonkhan for your such an outstanding lecture that you have summarized every necessary detail in it.

Question 1

Centralized exchange

In centralized exchange, all the transactions are made through a single authority. It works like a broker. In this exchange, Intermediaries play an important role because trade is done through them. Your all information can be regularly checked and verifies; authority can also take any action against them. In nutshell, every trade could be made with the involvement of a single or central authority.

Decentralized trade

In decentralized exchange, no broker is involved during any trade. Here trade is done in P2P mode. Both the traders are directly in contact with eachother and their information cannot be read/delivered to any central authority. One may say that this exchange is a direct exchange without the involvement of the central authority. Traders may take their own decisions freely. That’s why the decentralized exchange is considered the best exchange.

Question 2

Difference between centralized and decentralized exchange

1 In centralized exchange KYC (verification) is compulsory and complicated while in decentralized exchange, KYC is not necessary.
2 There is a central authority for doing any trade in centralized system while no central authority is in decentralized exchange.
3 Information is not secure in centralized while in decentralized, information remains secure.
4 centralized exchange is a high volume exchange while the other is less volume exchange.
5 charging fee is imposed on every transaction in centralized exchange while in decentralized exchange, no fee is charged.
6 In centralized exchange trade is made through brokers while in decentralized exchange P2P trade is done.

1 Binance

It is the most important exchange system. It is easy to use. It has a lot of users. There are many coins which can be traded thorough Binance. For new traders, it is the best exchange that I would like to refer because of its easy to use feature. However, it is also valuable because many brokers are available here 24/7 hours. However, verification of account is necessary and little bit complicated process in binance.

Bittrex global

It belongs to US crypto currency exchanges. It is more securable and trustable exchange. It is a centralized exchange. It also supports SBD and Steem trade, so it is also very valuable for steemit users that’s why I prefer to use it. It provides user friendly environment and it is very easy to use.

Question 4

How to install metamask

It is a wallet for crypto currency. Firstly, we have to install metamask extension in browser. For this purpose I used google chrome.

Search metamask on google.

A new screen will appear. Then click on download to create account on metamask.

Click on install metamask for chrome.

Then click on add extension to chrome because I am using chrome browser, you may select any browser of your own consent.

Here you have to click on get started for further procedure.

Because we are creating a metamask wallet, so here we click on create a walllet.

For further procedure, click on I agree button after reading the instructions carefully.

Here you have to create a password. Make sure that nobody could know about your password because it is a secret thing.

secret backup phrase will be generated copy it and paste it in its appropriate place.

you would see a message 'congratulation' on your screen. Here you have to click on all done.

Then click on start swapping.

your account will be shown and your metamask walllet has been generated.

Uniswap

Uniswap is a decentralized exchange which provide a friendly environment for business. Look ahead how we can sell or buy any item.
For this purpose, search Uniswap in goodle.

A screen would be appeared. Then click on use uniswap.

Here you have to join a wallet for trade. I selected metamask which I have already installed.

enter password and then click on next to connect with metamask.

Here you have to select any token as I selected ETH/USDT

after that actual balance has shown. Here the balance is 00 because it is difficult to make relation.

Because I have no balance to continue the business. you also submitt fees. After that you will make any transaction. For sell click on sale to take part in the crypto currency market.

for selling, click on sell button and a transaction would be made regarding your selected token.
At the end I would like to say thankx to @yousafharoonkhan who has delivered excellent lecture.
waiting for your positive response.