Used means something is not new because someone has it before. It is common for things like cars, clothes, or books.
I bought a used car last week.
This used book is very cheap.
Used means you are familiar with something because you do it often. It shows habits or experiences.
She is used to cold weather now.
I am used to waking up early.
Used as a verb means to do something with an object or idea. It shows action of applying or working with something.
I use a pen to write.
She used the phone yesterday.
Used means to take or spend something, like power or materials. It shows how much of something is consumed.
This machine uses a lot of power.
I used all the sugar for the cake.
Used can mean unfairly taking benefit from someone. It often shows bad or wrong behavior.
He used her kindness to get money.
Do not use people for your gain.
In the phrase 'used to', it shows something that happened regularly in the past but not now. It also shows habits now when followed by 'to'.
I used to play football as a child.
She is used to this kind of work.
Used in tech means storage or memory that is already taken or filled. It shows how much space is in use.
The used memory slows down the computer.
Check your used storage space on the device.