The difference is perceived mass distribution
A balanced bat tends to feel as though its mass is distributed more evenly through the swing. An end-loaded bat tends to create a stronger sense of mass toward the barrel. Slight end load sits between those descriptions. The printed bat weight alone does not explain how that distribution will feel to a particular player.
Compare control and barrel presence
Some players perceive a balanced bat as easier to accelerate or control. Others prefer the additional barrel presence of an end-loaded design. Neither load guarantees more distance, better contact or a particular swing result. Timing, comfort and the individual model still matter.
Change one variable during a test
Compare bats with the same listed weight and construction when evaluating load. Moving from balanced to end loaded while also changing weight and construction makes it difficult to understand which characteristic caused the difference you felt.
Confirm league requirements separately
Load preference does not determine whether a bat is permitted. Certifications and accepted stamps vary by league and tournament. Confirm current requirements directly with the organisation before purchasing or using a bat.