Type 1 is an autoimmune disease and specific markers are present. It usually happens at teens and younger.
The body destroys the isles of langerhans in the pancreas that produce insulin.

You need insulin to process glucose for energy to live. Your brain has to function, so when you have no insulin it must be injected for you to function and live.

Type 2 still produce insulin, but not enough to process the simple carbs (Sugars) and complex carbs (Carbs) we eat.
Insulin resistance is also a major factor.

A Type 2 can also become insulin dependent, but is still Type 2, not Type 1.

I know Type 2s that choose to shoot insulin, because they average 80- 100 carbs a meal and that is how they control their numbers.

But their lifestyle choices produce constant insulin spikes. Their constant weight gain, diabetes complications, and comorbidities reflect these choices. Their time in range and A1Cs reflect their choices.

There are less common types of diabetes too.

Type 1 Diabetes is an auto-immune disorder where your own body sees the pancreas as an "infection" and produces two different anti-bodies to "kill it" leaving you unable to produce your own insulin so the only treatment is insulin replacement

Type 2 Diabetes is a metabolic disorder where you may be insulin deficient (but still able and do produce some) but mostly your cells become resistant to using insulin to convert sugar to energy

That can be treated by anything from diet alone, to oral meds, to injectables to insulin replacement

Simply using insulin does not define your diabetes Type and Type 1's, Type 2's, LADA and MODY diabetics all may use insulin to control and those 4 types of Diabetes are mostly unrelated to one another

typr 1 doesnt produce any insulin while type 2 produces some ,but not enough .

Thanks so for you knowledge, love you guys💖