A unified theory has been developed on the basis of the
similarity in properties of perfect and allied types of functions. The theory
intromites as a starting point a certain subset of $\Cal P(X)$, the power set
of a nonvoid set $X$, and an operator $\alpha$ on $\Cal P(X)$; a second
operator $\beta$ is also brought into action. This theory of $\beta$-perfect
functions includes the theories of perfect, $\theta$-perfect and
$\delta$-perfect functions and is seen to generate many new types of functions
when different pairs of operators take the roles of the pair $(\alpha,\beta)$.
Keywords: $\beta$-perfect function, operator $\alpha$, $\beta$-set,
$\gamma$-set, $\beta$-closed function, $\beta$-convergence and
$\beta$-adherence of filter-bases.