Also known as conventional or regular cotton, standard cotton undergoes a less intensive milling process than ringspun cotton. The fibres are not spun in the same way, so the fabric is a bit rougher and less durable. Though they are cheaper to manufacture, t-shirts made from standard cotton can often lose their shape over time and may undergo significant wear and tear after several washes. Despite this, standard cotton is incredibly versatile and is used widely due to its lower cost. It is commonly used in clothing, home furnishing, medical supplies and various other applications.
When it comes to t-shirts, standard cotton is used for promotional goods or cheaper lines of clothing where the emphasis is more on cost-effectiveness than long-lasting luxury or resilience. If you're just getting a batch of branded t-shirts to wear to an event, there's no reason to splash out on the best of the best when just good will do. Similarly, if the t-shirt is likely to get damaged or stained, there's probably little point in spending more on durability and softness after several washes. So, t-shirts for people in the catering industry, mechanics, manufacturers or those working outdoors or with animals might be fine made of standard cotton.
So, the choice between ringspun and standard cotton depends on what you're using it for. If you need comfort and durability, or if you want a tee that'll stay in your wardrobe for years and become a staple, look for ringspun cotton in the description. If it's just something throwaway, for a promotion or where it's likely to get damaged, you might not be able to justify the extra expense of ringspun for a luxurious feel. Standard cotton isn't uncomfortable by any means - it's just a matter of degrees.