We all have our own definitions and tastes.  For me, pornography is anything that arouses, excites or titillates; whether we think it is bad, silly or nasty depends on our own individual tastes.  Arousal can be achieved by any or all of the five senses - sight, sound, touch, smell and taste.  Using our imagination is also vital.

Some people refer to pornography as though it was just about pictures and films.  For me, it goes much wider than that; for example, I would include many items of clothing.

I found this an interesting historical survey:

Pornography | Definition, History, Meaning, & Facts | Britannica

PHOTOS AND FILMS

Drawings, paintings and sculptures have used erotic subjects since the earliest times.  Photography dates from the end of the 1830s.  Nudes were soon a favourite subject.  Paris soon became well established as a centre of many studios producing postcards.  Although styled 'postcards' they were not usually sent my mail: they would have been banned.  They were sold by street vendors, tobacconists and other shops.  These photographs, produced from the 1840s until about 1920, were produced by a number of studios who often disguised their identity by using only initials or a pseudonym.  

The Internet has allowed and explosion in opportunities for nudity and sexual expression.  Women (and men) of all shapes, sizes and ages are posting photographs and films of themselves with no prohibitions on poses or sexual acts.  For some it will be a source of income but for many the purpose looks more like sexual satisfaction.  The Internet has helped me in several ways: I have found it reassuring to know that I am not alone in my attitudes and practices; it is a way of finding out whether I am normal.   

NUDITY

Is nudity always intended to cause arousal?  Traditionally, nudes have been a prominent part of paintings and sculptures.  Occasionally they have been depicted erect or with pubic hair but mostly without; women without hair or clitoris, with small, firm breasts and bottoms; muscular adult men have penises more appropriate to young boys.

When working as a nude model, I found that attitudes towards arousal varied from venue (or instructor) to venue.  The custom of referring to nude models as 'life models' says something about the unease of the art world with sexual activity.  The people I have met, both those in the class and the models, are not part of any nasty underworld culture; they are ordinary women and men of a wide range of ages and backgrounds.  We just have in common a view that there is nothing sinful about being naked and that it can be exciting and pleasurable.

The nudist beaches I have visited have varied in attitudes towards arousal.  For five years I lived near to Shoreham Harbour, a few miles west of Brighton on the south coast of England (deatils in post on masturbation web sites).  Between the harbour and the sea is an unofficial  nudist beach which was very liberal in attitudes towards erections, masturbation and intercourse; others I have visited were much more prudish.  There are many nudists who want to dissociate nudism from any kind of sexual excitement.

TOYS

One of the most common kind of sex toy are those to act as a substitute for an erect penis.  Some for the ladies are double, one for her anus, one for her vagina.  Some vibrate for extra stimulation, some are like a smooth string of beads of variable width.   

There are various kinds of penis stimulator.  A penis pump can cover the whole penis and help it grow by creating a vacuum which encourages the inflow of blood; a penis ring can then help maintain an erection.   

CLOTHING

What are the purposes of low-cut dresses and tops?  Or slit-sided skirts leading the eye to the wearer's breasts or up her legs?  Aren't they intended to excite?  And what about tight-fitting trousers or leggings, showing off her panty-line and bottom, especially if worn with a tight-fitting, short top?

For many of us, our underwear is a mean of arousal and a feeling of well-being.  Some men and women like to wear   skimpy thongs or G-strings for their appearance as well as for anal stimulation as they rub along their crevices.

Many of us enjoy the feel full back knickers caressing our cheeks.  Sexual stimulation is often used as a selling point for knickers and panties.  'Vanity fair' is an expression often used by mainstream retailers on their on-line sites and high street stores for full back, high waist knickers, many of them in soft satin, caressing the cheeks.  There is a hint of self-indulgence, sin, decadence and transgression, perhaps relating to their stimulating effect in preparation for sexual pleasures including masturbation.  (Vanity Fair was originally described as a stop along the pilgrim's route where there was never-ending attachment to self-pleasure in Pilgrim's Progress by John Bunyan (1678) and later taken up by William Makepeace Thackeray in Vanity Fair (1848).)  Some brands have a triangular net or lace inset at the side of each leg about 3 or 4 inches wide at the leg hole rising to an apex about the same distance above - leading thoughts to the forbidden fruits within?

The unisex fixation knickers which I always wear are similar to ladies' knickers except that they do not have a gusset.  Instead, I wear a pad extending from about an inch below my navel to an inch or two above my bum crevice to absorb anything from either outlet.  They are more stretchy than male underwear.  Some are made of white lycra netting, others of white elastane and polyester (details in my journal Incontinence Wear).

ADDICTION

I would not like to completely avoid pornography: indeed, in my view of what it encompasses, it would be nearly impossible to do so.  When my erogenous areas are sending out their signals, a little porn helps me to masturbate, as described on the masturbation web sites.  There are widely held views on the benefits of masturbation: reduces stress; improves muscle tone in the anal and pelvic areas; reduces the risk of prostate cancer; reduces menstrual cramps and muscle tension; improves self-esteem; see for example:

Masturbation: Health Benefits, Side Effects, Myths, FAQs (healthline.com)

10 Benefits of Masturbation - How Masturbating Boosts Your Health (menshealth.com)

17 Benefits Of Masturbation: Why Masturbating Is Good For You | mindbodygreen

Masturbation: Facts & Benefits (clevelandclinic.org)

However, for some people, pornography addiction is a problem: it can take over their lives and prevent them going about their work and pursuing other interests.  They get involved with chat rooms and paid-for sites.  It can ruin relationships with spouses and others.  I have found that I can take my mind off it by reminding myself that much of it is faked and/or sad, silly or duplicitous.  After a while I become tired of being bombarded by silly advertisements treating the viewers as half-wits: so I stimulate a hard orgasm and ejaculation and remind myself that there are other more important activities that I should be doing; after all, it's only a bit of fun.  Similarly for masturbation: one orgasm has usually been enough for me to put my mind to other things.

All of what I have written is, of course, only my own view.  How does it compare with yours?