Which ORF will be translated
If both of the ORFs that the web tool predicted start with an AUG initiation codon, then the textbook answer is that the 5' cap on eukaryotic mRNAs is the first feature that is recognized by the translational apparatus, and the ribosome scans along until it finds the first AUG (it is a simplified description). However, if there are several AUGs near each other then the one that matches the best to the Kozak PWM (position weight matrix) will be preferred. The Kozak sequence can be approximated by: CCATGG which is also recognized by the restriction enzyme NcoI. Highly expressed genes tend to match most closely to the Kozak consensus.