Difference between Useless and Useful

USELESS vs USEFUL: ADJECTIVE

Of great importance or use or service
Capable of being turned to use or account
Being of use or service
Having a useful function
Having a beneficial use; serviceable.
Being of practical use.
Full of use, advantage, or profit; producing, or having power to produce, good; serviceable for any end or object; helpful toward advancing any purpose; beneficial; profitable; advantageous.
Having a practical or beneficial use.

Having no use; being of no use; unserviceable; usable to no good end; answering no valuable purpose; not advancing the end proposed; unprofitable; ineffectual.
Synonyms Useless, Fruitless, Ineffectual, Unavailing, bootless, profitless, unprofitable, valueless, worthless, futile, abortive. Useless often implies that the cause of failure lies in the situation; as, it is useless to try to mend that clock. Useless is the only one of these words that may thus be applied by anticipation to what might be attempted. That which is fruitless, ineffectual, or unavailing actually fails, and from hindrances external to itself. Unavailing is more likely to be used the fruitless or ineffectual where the failure is through some one's unwillingness; as, unavailing prayers or petitions, ineffectual efforts, fruitless labors. Fruitless is stronger and more final than ineffectual or unavailing.

Useful invention.
Being of use, advantage, or profit; valuable for use; suited or adapted to a purpose; producing or having power to produce good; beneficial; profitable; serviceable.

Cast off, Scrap, Waste, Unprofitable, Junked, Unavailing, Unserviceable, Discarded, Otiose, Inutile, Unhelpful, Unuseable, Ineffectual, Unusable, Futile

Recyclable, Multipurpose, Reusable, Reclaimable, Utilizable, Utile, Utilitarian, Serviceable, Functional, Useable, Usable, Practical, Important, Valuable, Helpful

Cast off, Scrap, Waste, Unprofitable, Junked, Unavailing, Unserviceable, Discarded, Otiose, Inutile, Unhelpful, Unuseable, Ineffectual, Unusable, Futile

Recyclable, Multipurpose, Reusable, Reclaimable, Utilizable, Utile, Utilitarian, Serviceable, Functional, Useable, Usable, Practical, Important, Valuable, Helpful

The principal, teachers and IT staff are useless.
It does not make you a useless idiot.
Otherwise, they risk being misunderstood and therefore useless.
TRIED CALLING MTNL CUSTOMER CARE BUT ASUSUAL USELESS.
How The Meta is Shifting; Most Useless Commander?
Program sandbags are useless without having the bodyweight!
Stop wasting your time with those useless methods.
Cut all the useless clubs, the unnecessary tables, the investments that are fun to be in but useless to the bottom line.
While the temptations to go in useless or worse than useless direction, certainly exists, there are amazing things on the internet.
If Christ was not raised, then all our preaching is useless, and your trust in God is useless.

Get useful insights to help make better decisions.
This option is only useful to Guix developers.
Three additional categories of area formulas are useful.
They identify the useful energy forms and the desired output of the device, and the forms that are not useful for the intended use.
Useful Summation Formulas We can use the notation to indicate useful formulas that we will have occasion to use.
This is useful for maintaining correct release times for software and is particularly useful in conjunction with the MKS Make software development facility.
As always, if you find this article useful then others may find it useful too.
The guide is quite useful, and has useful pictures accompanying the text.
Gems of Useful Knowledge Life hacks, practical tips and overall useful information.
Please provide examples of how they are useful or not useful.