Concept:
Spam refers to unwanted or unsolicited e-mails that are sent in bulk to a large number of users, usually for advertising, promotions, phishing, or fraudulent purposes.
Spam emails consume storage space, waste users' time and may also contain malicious links or attachments.
• Sent without the recipient's permission.
• Usually sent in large quantities.
• May contain advertisements, scams or malware.
• Most email services automatically filter spam messages.
Step 1: Understand the meaning of unsolicited e-mail.
An unsolicited e-mail is one that is:
\[
\boxed{\text{Sent without the recipient requesting or expecting it.}}
\]
Such unwanted commercial emails are called Spam.
Step 2: Differentiate the given options.
• Trash -- Folder containing deleted emails.
• Spam -- Unwanted commercial emails. (Correct)
• Archive -- Folder used to store emails without deleting them.
• Virus -- A malicious software program, not an email category.
Step 3: How can spam be avoided?
Spam can be reduced by:
• Using spam filters.
• Avoiding sharing email addresses publicly.
• Not opening suspicious links or attachments.
• Marking unwanted emails as spam.
Step 4: Final conclusion.
Hence, unsolicited commercial e-mail is known as:
\[
\boxed{\text{Spam}}
\]