These terms are used in pediatric studies and have minor distinctions
Consent for adults:
For the conduction of clinical research studies and trials, recruiters recruit patients for the trials and for this purpose, the patients who are willing to participate in trials sign-off an agreement and documents that involved all the processes and risk associated with the clinical research trials and these are named as informed consent forms and that process is called informed consent process.
Signing consent is not an issue for they adults and they can give proper consent by the PIs and study coordinator by properly understanding the process and risks involved in clinical research trials.
Assent for children:
This is also an agreement that is signed by the patient who is willing to participate in trials but only when he is under 18 because it is not considered legal.
Less than 18 years of age participants have to sign off an assent and adult also has to sign off consent form on behalf of that child. Consent can be signed by his guardian or parents.
They are unable to move forward in clinical trial process when they are missing any of the consent and assent documents.