Pliers and Pair of tongs

Pliers noun - A gripping hand tool with two hinged arms and (usually) serrated jaws.

Pair of tongs and pliers are semantically related. In some cases you can replace phrase "Pair of tongs" with "Pliers", this terms are similar.

Pair of tongs noun - Any of various devices for taking hold of objects; usually have two hinged legs with handles above and pointed hooks below.

Pliers and pair of tongs are semantically related. You can use "Pliers" instead a noun phrase "Pair of tongs".