The most basic examples of oscillation are rocking in a cradle and swinging on a swing. If you will think critically then you will realize that in both of these examples the motion is repetitive and the swing or cradle goes to and fro about a specific point. Another example is the pendulum wall clock, in which the pendulum repeats its motion periodically. If many objects come together and do oscillatory motion then they form a wave. In order to understand the former statement consider the disturbance created in a pond when you drop a stone in the still water. It will seem like the disturbance (ripples) is moving outwards in the circular form. But if you will place cork on the disturbance you will see that the cork is not moving outwards it will be just oscillating where you placed it. The disturbance is a form of a wave in which the energy is transferred from one particle to another rather than actual physical transfer.
Oscillation: Periodic motion: period, frequency and displacement as a function of time. Periodic functions. Simple harmonic motion, equation of SHM, phase. Oscillation of spring, spring constant and restoring force. Energies in SHM: kinetic and potential energies. Simple pendulum, derivation of the time period of a simple pendulum. Free, forced, and damped oscillations, resonance
Waves: Longitudinal and transverse wave, wave speed, displacement relation for progressive wave, superposition and reflection of waves. Standing waves in the string and organ pipes, harmonics and fundamental mode, beats, dopplers effect
Oscillatory motion is a type of periodic motion but in this motion, the object moves to and fro about the mean position in regular interval of time. It is important to understand that every oscillatory motion is periodic motion but every periodic motion is not oscillatory. For example, the rotation of the earth around the sun is periodic but not oscillatory. In this chapter, you will mainly have to read about Simple Harmonic Motion (SHM). SHM is the simplest form of oscillatory motion in which the restoring force is directly proportional to the displacement of the particle. Where Retarding force is a force which acts on the particle or object to bring it back to its rest position. Now let's understand some basic terms related to Oscillatory Motion :
Time Period  The smallest interval of time after which the motion starts to repeat itself is known as the time period. It is denoted by T.
Frequency  It represents the number of repetition of motion per unit time. In other words, it is reciprocal of the time period. It is denoted by f.
Periodic Function  A function which could be expressed by the superposition of sine and cosine functions of different time periods and suitable coefficients.
Amplitude  It is a positive constant which represents the maximum displacement of the particle in either direction. It is denoted by A.
Phase constant  A phase constant is the initial position/phase of a particle in SHM. It is denoted by .
A wave, on the other hand, consists of the oscillatory motion of the various particle and gradually these oscillations of particles propagate to other points without the actual transport of matter. Equation of waves can also be described by the terms which are mentioned above.
A wave can be classified in three manners :
Oscillations
Time period for spring oscillator,
Time period for simple pendulum,
Waves
General Equation of sine wave 
Phase Difference,
Wave speed,
When solving questions for both these topics always keep in mind that your concepts should be clear. Most of the questions in this chapter won’t require long calculation, rather they will be concept based. Hence the questions from these chapters are easy but conceptual. You could master both these chapters by practicing more. If you face any problem in solving the question read the topic again and solve. Give mock tests to build confidence. In oscillations and waves, you will find many equations so get familiar with these equations and understand the meaning of each term in the equation.
Frequently revise your notes, and make a list of weak topics and practice more on that.
You should be able to convert one entity to another, example  converting time period into angular frequency. Don’t get confused about angular frequency and frequency.
Give more attention to Standing waves in organ pipe and string, Doppler’s effect, and resonance.
Clear your doubts with your teacher or classmates or authenticated online resources.
Always write down what is given in the question.
For questions related to oscillations and waves you should, first of all, go through NCERT with giving attention to examples. Try to solve each and every question of NCERT question. For getting more insights about the chapter, solve questions from NCERT Exemplar. But apart from these books, you should also give topicwise online mock tests. We will provide you with chapter articles of all the chapters, in simple language to make learning easy and a variety of questions in mock tests.
Chapters No. 
Chapters Name 
Chapter 1 

Chapter 2 

Chapter 3 

Chapter 4 

Chapter 5 

Chapter 6 

Chapter 7 

Chapter 8 

Chapter 9 

Chapter 11 

Chapter 12 

Chapter 13 

Chapter 14 

Chapter 15 

Chapter 16 

Chapter 17 

Chapter 18 

Chapter 19 

Chapter 20 

Chapter 21 
A block of mass 0.1 kg is connected to an elastic spring of spring constant 640 Nm^{−1} and oscillates in a damping medium of damping constant 10^{−}2 kg s^{−1. } The system dissipates its energy gradually. The time taken for its mechanical energy of vibration to drop to half of its initial value, is closest to :
2 s
3.5 s
5 s
7 s
Two particles are executing simple harmonic motion of the same amplitude A and frequency along the axis. Their mean position is separated by distance . If the maximum separation between them is , the phase difference between their motion is
The transverse displacement of a wave on a string is given by
This represents a