Comparison between inner join and normal

I just would like to know the difference between this two type of sql query

1. SELECT [Last Name], InvoiceDate, Amount
FROM tblCustomers INNER JOIN tblInvoices
ON tblCustomers.CustomerID=tblInvoices.CustomerID
ORDER BY InvoiceDate

2. SELECT [Last Name], InvoiceDate, Amount
FROM tblCustomers, tblInvoices WHERE
tblCustomers.CustomerID=tblInvoices.CustomerID
ORDER BY InvoiceDate

Thank you.