In this array are registered all module templates blocks. On module activation they are automaticly inserted into database. On activating/deactivating module, all module blocks also are activated/deactivated.
array of arrays. Sub keys can be template, block, file and position.
'blocks' => [
        'template' => 'widget/sidebar/partners.tpl',
        'position' => '2'
        'template' => 'page/checkout/basket.tpl',
        'position' => '1'
        'template' => 'page/checkout/basket.tpl',

Differences in block file definition per shop/metadata version.

In OXID eShop >= 4.6 with metadata version 1.0 template block file value was relative to out/blocks directory inside module root.

In OXID eShop 4.7 / 5.0 with metadata version 1.1 template block file value has to be specified directly from module root.

To maintain compatibility with older shop versions, template block files will work using both notations.

Template block file value holding path to your customized block should be defined using full path from module directory, earlier it was a sub path from modules out/blocks directory.

You can define a position of a block if a template block is extended multiple (by different modules). So you can sort the block extensions. This is done via the optional template block position value.