The statement "when one person signifies to another his willingness to do or abstain from doing anything with a view to obtaining the assent of that other person to such act or abstinence" refers to making a "proposal" or an "offer." This is defined under Section 2(a) of the Indian Contract Act, 1872, which states that such an expression of willingness by one person to another to do or abstain from doing something, aiming to get the other's assent, is called a proposal or an offer. The person making the offer is called the offeror (or promisor), and the person to whom the offer is made is the offeree (or promisee).
In summary, when this willingness is communicated with intent to obtain assent, it is said that the person makes a proposal or offer.