Abstract
Refers to ideas or concepts; they have no physical referents. They are fine when used for Main Ideas of a paragraph or Thesis.

[Stop right here and reread that definition. Many readers will find it both vague and boring. Even if you find it interesting, it may be hard to pin down the meaning. To make the meaning of this abstract language clearer, we need some examples.]

Examples of abstract terms include love, success, freedom, good, moral, democracy, and any -ism (chauvinism, Communism, feminism, racism, sexism). These terms are fairly common and familiar, and because we recognize them we may imagine that we understand them—but we really can't, because the meanings won't stay still.

Take love as an example. You've heard and used that word since you were three or four years old. Does it mean to you now what it meant to you when you were five? when you were ten? when you were fourteen (!)? I'm sure you'll share my certainty that the word changes meaning when we marry, when we divorce, when we have children, when we look back at lost parents or spouses or children. The word stays the same, but the meaning keeps changing.

If I say, "love is good," you'll probably assume that you understand, and be inclined to agree with me. You may change your mind, though, if you realize I mean that "prostitution should be legalized" [heck, love is good!].

How about freedom? The word is familiar enough, but when I say, "I want freedom," what am I talking about? divorce? self-employment? summer vacation? paid-off debts? my own car? looser pants? The meaning of freedom won't stay still. Look back at the other examples I gave you, and you'll see the same sorts of problems.

Does this mean we shouldn't use abstract terms? No—we need abstract terms. We need to talk about ideas and concepts, and we need terms that represent them. But we must understand how imprecise their meanings are, how easily they can be differently understood, and how tiring and boring long chains of abstract terms can be. Abstract terms are useful and necessary when we want to name ideas (as we do in thesis statements and some paragraph topic sentences), but they're not likely to make points clear or interesting by themselves. 

Concrete
Refer to objects or events that are available to the senses. They can be: Seen, Head, Felt, Touched, Smelled.
This is directly opposite to abstract terms, which name things that are not available to the senses.] Examples of concrete terms include spoon, table, velvet eye patch, nose ring, sinus mask, green, hot, walking. Because these terms refer to objects or events we can see or hear or feel or taste or smell, their meanings are pretty stable. If you ask me what I mean by the word spoon, I can pick up a spoon and show it to you. [I can't pick up a freedom and show it to you, or point to a small democracy crawling along a window sill. I can measure sand and oxygen by weight and volume, but I can't collect a pound of responsibility or a liter of moral outrage.]

While abstract terms like love change meaning with time and circumstances, concrete terms like spoon stay pretty much the same. Spoon and hot and puppy mean pretty much the same to you now as they did when you were four.

You may think you understand and agree with me when I say, "We all want success." But surely we don't all want the same things. Success means different things to each of us, and you can't be sure of what I mean by that abstract term. On the other hand, if I say "I want a gold Rolex on my wrist and a Mercedes in my driveway," you know exactly what I mean (and you know whether you want the same things or different things). Can you see that concrete terms are clearer and more interesting than abstract terms?

If you were a politician, you might prefer abstract terms to concrete terms. "We'll direct all our considerable resources to satisfying the needs of our constituents" sounds much better than "I'll spend $10 million of your taxes on a new highway that will help my biggest campaign contributor." But your goal as a writer is not to hide your real meanings, but to make them clear, so you'll work to use fewer abstract terms and more concrete terms.

General and Specific

General terms and specific terms are not opposites, as abstract and concrete terms are; instead, they are the different ends of a range of terms.General terms refer to groups; specific terms refer to individuals—but there's room in between. Let's look at an example.

Furniture is a general term; it includes within it many different items. If I ask you to form an image of furniture, it won't be easy to do. Do you see a department store display room? a dining room? an office? Even if you can produce a distinct image in your mind, how likely is it that another reader will form a very similar image? Furniture is a concrete term (it refers to something we can see and feel), but its meaning is still hard to pin down, because the group is so large. Do you have positive or negative feelings toward furniture? Again, it's hard to develop much of a response, because the group represented by this general term is just too large.

We can make the group smaller with the less general term, chair. This is still pretty general (that is, it still refers to a group rather than an individual), but it's easier to picture a chair than it is to picture furniture.

Shift next to rocking chair. Now the image is getting clearer, and it's easier to form an attitude toward the thing. The images we form are likely to be fairly similar, and we're all likely to have some similar associations (comfort, relaxation, calm), so this less general or more specific term communicates more clearly than the more general or less specific terms before it.

We can become more and more specific. It can be a La-Z-Boy rocker-recliner. It can be a green velvet La-Z-Boy rocker recliner. It can be a lime green velvet La-Z-Boy rocker recliner with a cigarette burn on the left arm and a crushed jelly doughnut pressed into the back edge of the seat cushion.By the time we get to the last description, we have surely reached the individual, a single chair. Note how easy it is to visualize this chair, and how much attitude we can form about it.

The more you rely on general terms, the more your writing is likely to be vague and dull. As your language becomes more specific, though, your meanings become clearer and your writing becomes more interesting.

Does this mean you have to cram your writing with loads of detailed description? No. First, you don't always need modifiers to identify an individual: Bill Clinton and Mother Teresa are specifics; so are Bob's Camaro and the wart on Zelda's chin. Second, not everything needs to be individual: sometimes we need to know that Fred sat in a chair, but we don't care what the chair looked like.

Summing Up

If you think back to what you've just read, chances are you'll most easily remember and most certainly understand the gold Rolex, the Mercedes, and the lime green La-Z-Boy rocker-recliner. Their meanings are clear and they bring images with them (we more easily recall things that are linked with a sense impression, which is why it's easier to remember learning how to ride a bike or swim than it is to remember learning about the causes of the Civil War).

We experience the world first and most vividly through our senses. From the beginning, we sense hot, cold, soft, rough, loud. Our early words are all concrete: nose, hand, ear, cup, Mommy. We teach concrete terms: "Where's baby's mouth?" "Where's baby's foot?"—not, "Where's baby's democracy?" Why is it that we turn to abstractions and generalizations when we write?

I think part of it is that we're trying to offer ideas or conclusions. We've worked hard for them, we're proud of them, they're what we want to share. After Mary tells you that you're her best friend, you hear her tell Margaret that she really hates you. Mrs. Warner promises to pay you extra for raking her lawn after cutting it, but when you're finished she says it should be part of the original price, and she won't give you the promised money. Your dad promises to pick you up at four o'clock, but leaves you standing like a fool on the corner until after six. Your boss promises you a promotion, then gives it instead to his boss's nephew. From these and more specific experiences, you learn that you can't always trust everybody. Do you tell your child those stories? More probably you just tell your child, "You can't always trust everybody."

It took a lot of concrete, specific experiences to teach you that lesson, but you try to pass it on with a few general words. You may think you're doing it right, giving your child the lesson without the hurt you went through. But the hurts teach the lesson, not the general terms. "You can't always trust everybody" may be a fine main idea for an essay or paragraph, and it may be all that you want your child or your reader to grasp—but if you want to make that lesson clear, you'll have to give your child or your reader the concrete, specific experiences

Abstract

Ideas, thoughts, opinions, theories, concepts, points of view, attitudes, etc

Use: MI (Topic Sentence) or Thesis 

Concrete

Things you can: see, hear, taste, touch, smell

Real people, Real places, Real things etc.

Use: Supports abstract statements-Develops these ideas
 

Abstract: happy, content, carefree-----beautiful day

Concrete: wagging tail, smiling face, laughing boy----- warm sunny 80 degree clear bright azure blue sky

Abstract: caring, thoughtful, concerned

Concrete: donates 10% of her pay to charity every week

Abstract: Sally and her family enjoyed a relaxing fun filled day at the beach.

Concrete: Sally's family brought lot of snacks to the beach, swam for hours,  and made sand castles in the warm sunshine

Abstract: Everyone loves Mary; she is very outgoing and friendly.

Concrete: At the party Mary talked to just about everybody there, and offered to help the host clean up after it was over.

Abstract: My cousin is really successful, and has a great attitude which why I enjoy his company and advise.

Concrete: Jake, my older cousin, works for a local law firm as a paralegal. He helped me with my court appearance for a parking ticket, but warned me that the best way to avoid being brought to court is to obey the law.

Abstract: My best friend Eugene enjoys letting loose and having fun

Concrete: Last Friday Eugene and I went to Great Adventure Amusement Park and went on about 20 different rides. We

Abstract: I love Ann because not only is she beautiful both inside and outside, but because she really cares about other people.

Concrete: Because of her sandy blond long straight hair and silky smooth complexion, every where Jackie goes heads turn. However, she says, "looks are not important; it is how you live your life that counts."  She means it because twice a week she volunteers at our local senior citizen's home to read to elderly people.

Abstract: It was a huge and frightening dog

Concrete: This monstrous German Shepherd looked like he weighted about 75 pounds, and his teeth were bared for action.