You need a merchant account to do anything "sales" online other than Ebay.
To accept payments you need to use a merchant account and payment processor. The payment processor links to your bank and merchant account.
2 ways of doing this involve using a third party gateway like paypal or direct to your bank if you can.
Direct is often cheaper and has more benefits.
1 The Bank has insurance on fraud, pay pal claims it does but attempting to prove anything with pay pal is like using a toothpick to break through a concrete wall.
2 There are no limits on fraud cover with a bank. The crime is a crime, they have to protect their customers and themselves, pay pal is company not bound by banking laws and ay excuse to worm out of something is good for them.
3 You save tax and payment costs by going direct. Depending on where you live, GST / VAT is applied to your sale transfer rates.
The payment processor eway , pay pal charge a free / transaction, so does the bank. each time it adds tax.
Then you have other issues like annual charges, account fees, access charges. On the whole though, a bank is cheaper than a gateway, they don't charge extra for security and insurance, a payment processor often does.
Also a bank will never open a paypal account with someone elses credit card and start purchasing for NIgeria.