The word "organic" looks good on the shelf, but you need to know what lies behind it. Organic cotton is cotton grown without synthetic pesticides or genetically modified seeds. That is a real difference for the soil and for the health of farmers.
But note: the fact that the cotton is organic does not, on its own, tell you what the fabric was exposed to during dyeing and finishing. This is where the type of certification matters. GOTS covers the whole process from field to finished product; it sets criteria for dyes, chemicals and even working conditions. Some standards, such as OCS, only verify that the product contains organic cotton and do not cover processing.
It is also a common misconception that organic cotton is automatically softer. Softness depends on fibre length, yarn and weave. And then there is Oeko-Tex, which is something else again: it shows that the product has been tested for harmful substances, not whether it is organic. A serious brand prints the certificate number on the label, and you can check that number on the certification body's website. It takes five minutes and tells you a lot.