What is the difference between comprehensive and targeted sanctions, and why did sanctions design shift towards targeted ones?

Question

Accepted Answer

Comprehensive sanctions hit a country's economy as a whole; targeted sanctions burden only the state representatives responsible for the war or the human-rights violations. The shift came because comprehensive sanctions harm civilians, which violates the principle of discrimination.
Economic sanctions are the "soft weapons" of hybrid warfare, used as an alternative or a complement to military force. Typical measures:

restricting imports or exports of certain goods or sectors,
boycotting trade relations,
freezing the assets of the target state's representatives.

Comprehensive sanctions weaken the whole economy to limit the state's capacity to wage war. But the weakest groups suffer most, as the government cuts social and health spending.
Targeted sanctions apply the just-war principle of discrimination. They should burden only those responsible, and sanctioning states explicitly exempt vital goods such as food, agricultural and medical products. That exemption shows they do not intend to target civilians' basic needs, which keeps the sanctions discriminating and proportionate.