Deckard is a bounty hunter in the regular employment of the San Francisco police department. His regular salary is low but he earns 1000 dollars for every android he destroys. there's not much life left on Earth. Most of the plants and animals were either killed in the nuclear war or died later from radiation poisoning. Those left are still deteriorating and dying. Unaffected survivors were persuaded to colonise other planets and were offered android 'slaves' as an incentive. So Deckard and his wife now live in a dry, barren, depopulated city where radioactive dust and escaped androids are the big problems. The diminishing fertility of the few remaining healthy men is guarded by lead codpieces. The most expensive, prestigious and coveted commodity is an actual living animal - even a spider or a toad is highly valued. Deckard and his wife own an electric sheep which they keep on the roof of their apartment building. They're ashamed of it. If Deckard could 'retire' 3 androids, the 3000 dollar bounty would be enough for a down-payment on a real ostrich or a goat. This is his ambition.
If you've watched 'Blade Runner', it might strike you that this, the book it was based upon, tells a very different story. This Deckard bears little resemblance to the Harrison Ford Deckard. The android characters are equally dissimilar to those in the film. The way they're tested (in book and film alike) is by asking them a series of questions, the answers to which reveal whether they have empathy. Androids fail the empathy test. Whereas the film androids failed the test, they then went on to behave empathetically. The book androids, on the other hand, confirm the test results in their cold behaviour, not only to their enemies, but to each other. Even so, Deckard finds enough 'life' and humanity in these entities to stimulate his own sense of empathy.
I did enjoy the film very much - though P K Dick was distressed by it apparently. The book is a completely different experience: more sad, dour, down-beat, more complicated, more thought provoking, less technologically flashy and colourful. Loving the film is no guarantee of loving the book, or vice versa. I recommend them both.