Greenhouse - usually smaller size, glass, diretct sun, gets warm quickle. grow toms, peppers etc, easily heated. Can get very hot in Summer

Hybrid polyhouse - gets warm quickly and stays warm. No direct Sun, great for starting seeds, climate controlable, heatable in early/late/Winter season.

Polytunnel - Usually too big to heat adequately, no direct sun, loads of spact to move seedlings into for protection and hardening off early season. Will support outdoor crop for earlier results.

Hope this helps

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