Homophones are words that sound the same but have different meanings. The different meanings often have different spellings.
The words to, too and two are homophones.
Too means 'as well' or 'also'.
For example: Katie likes chocolate ice cream and Sarah does too.
We also use it when we mean 'too much' or 'too many'.
Jessie ate too much ice cream and was sick.
It was too hot for me outside so I came indoors.
Two always means the number 2.
Otherwise, we use the word to.
I am going to Jimmy's house tomorrow.