What do you mean by Limits and continuity?

Understand the meaning of Limits and continuity. click on the link toWatch the VIDEO Explanation: Watch Video

Limits and continuity
Real Function
A real valued function f or simply a real function f is a rule which associates to reach possible real number x, a unique real number f (x)
Value of a function
If f is a function and x is an element in the domain of f, then images f (x) of x under f is called the value of f at x.
Types of function and their graph
Constant Function
F (x) is equal to k is called a constant function.
Identify function
The identify function is defined as f (x) is equal to x.
Exponential function 
The Exponential function is defined f (x) is equal to e x
Logarithmic function
Logarithmic function F (x) is equal log x
Trigonometric functions such as sin x, cos x, tan x etc
Inverse functions such as sin inverse x, cos inverse x, tan inverse x etc
Modulas Functions
Signum functions
Reciprocal functions
Note 1:
We say that f(x) is continuous at every point in its domain.
Note 2:
If f and g are two continuous functions then f plus g, f minus g are continuous functions.
Note 3:
Every polynomial function is continuous at each point of its domain.
Note 4:
Every rational function is continuous at each point of its domain.
Note 5:
Composition of two continuous functions is continuous.