• Each row can be styled:

td {border:solid blue 2pt}
th {border:solid red 1pt}
table {border:dotted green 3pt;  border-collapse:collapse}
tr {background-color:white}

All the table rows are white.

• Each row can be styled differently using the class selection:

td {border:solid blue 2pt}
th {border:solid red 1pt}
table {border:dotted green 3pt;  border-collapse:collapse}
tr.one {background-color:white}
tr.two {background-color:pink}
tr.three {background-color:navajowhite}

All the table rows have different backgrounds