IN'TO, preposition [in and to.]
- Noting entrance or a passing from the outside of a thing to its interior parts. It follows verbs expressing motion. Come into the house; go into the church; one stream falls or runs into another. Water enters into the fine vessels of plants.
- Noting penetration beyond the outside or surface, or access to it. Look into a letter or book; look into an apartment.
- Noting insertion. Infuse more spirit or animation into the composition.
- Noting mixture. Put other ingredients into the compound.
- Noting inclusion. Put these ideas into other words.
- Noting the passing of a thing from one form or state to another
IN, preposition [Latin in ]
- in denotes present or inclosed, surrounded by limits; as in a house; in a fort; in a city.
- It denotes a state of being mixed, as sugar in tea; or combined, as carbonic acid in coal, or latent heat in air.
- It denotes present in any state; as in sickness or health.
- It denotes present in time; as in that hour or day.
American Dictionary of the English Language (1828) - http://webstersdictionary1828.com/
"In" is a prepostion which is usually used for something that is not moving and that's already in.
e.g. The bananas are in the refregerator.
In above example in is used with no moving.
"Into" is used when someone or something is going or moving.
E.g. I am putting the bannanas into the refregerator.
In this example I moved from on place to another.