Demonstratives are words like this & that in English. They are used in Japanese and they follow a ko, so, a & do pattern. Their uses are pretty straight forward.
The ko series refers to things close to the speaker, so series refers to things a little farther away or closer to the listener and a series refers to things farther away, out of reach from both the speaker and listener. Do series is used for question form.
There are two different sets of words used for this and that. They both mean the same thing but which one you use depends on what words are around it. Those than end in re have to be used beside a particle. Those that end in no are used directly beside a noun.
This book = kono hon (この本)
That tree = ano ki (あの木)
This is pen = kore wa pen desu (これはペンです)
That is TV = sore wa terebi desu (それはテレビです)
That is me = sore wa watashi desu (それは私です)
The words that end in ko are used for a location. Words that end in nna are used for feelings, ideas or nouns.
(It's) here = koko da (ここだ)
Notebook is there = nooto wa soko desu (ノートはそこです)
Pencil is over there = enpitsu wa asoko desu (えんぴつはあそこです)
What kinda movie? = donna eiga? (どんな映画？)
Those that end in chira & cchi both mean the same thing except the ones that end in chira are only used in polite situations, the other is casual. Itsu endings are not necessarily used to refer to the male gender only, but can be used to refer to a person in a casual situation.
When you are introducing someone it is more polite if you use the direction words above (~chira). Using them this way is kind of like saying here we have...
This is Tom = kochira wa tomu desu (こちらはトムです)