Different between Black Hat and White Hat SEO techniques

AbraKaDabraI was reading about SEO and came across two terms : Black Hat SEO and White Hat SEO.

Could someone explain what exactly is the difference between the two? Does black symbolize something unethical?

How can SEO be unethical?

Balck Hat Refers to as the Term which says "something which is against search engine policies"

example

1) Creating texts with the same color as backcolor for keyword stuffing
2) Showing separate pages to search engines and separate pages to visitors
3) Link purchase

etc,

white Hat simply are the allowable techniques:

adding meta and description to the pages
using proper 301 redirections
using links from authority sites. etc

For a layman like me, It seems like I am not getting a thing.
Tell us do we unknowingly use this Black Hat SEO?

P.S: While publishing blog, I fill SEO titles.

Publishing articles with a SEO title isn't a 'black hat' technique. However, it could be seen as a black hat technique because you show one title to visitors and other to the search engines. Sometimes, you might want to write a magnetic headline that attracts visitors but does not make a good headline for the search engines. One of the most common black hat SEO technique is purchasing links on higher ranked blogs.

Thanks Biggie. I think I am getting the feel of things. Between, what do you mean by "purchasing links on higher ranked blogs?" 😀
Is it similar to spamming?
For example, if someone spamming a higher ranked website with the links of his/her lower rank website?

My opinion - very personal opinion, may be - The world fights for Black or White issues but same time "Gray" has made his place in group of white.. Black Hat techniques are tactics to cheat search engines and white hat techniques are going normal as per search engines theories. When we say white hat, I feel that actually we are using gray as we first understand how search engines reacts and then we start acting like that only. After all human rules computers ....